CHEMISTRY FOR BEGINNERS: 



WITH ENGRAVINGS. 



BY MRS. A. H. LINCOLN PHELPS, 

Author of Familiar Lectures on Botany, Dictionary of Chemistry, Lectures to 
Young Ladies, &c. 




HARTFORD: 
PUBLISHED BY F. J. HUNTINGTON. 

1834. 



Entered according to Act of Congress, in the year 1834, by 

F. J. Huntington, 
in the Clerk's Office of the District Court of Connecticut. 



>to-fr. 



J. S. and C. Adams, Printers, Amherst. Ms. 



PREFACE. 



The design of this work is to teach Chemistry to beginners. 
The author has sought to present the elements of the science in a 
popular and attractive form, without offending the scholar by 
marring its classical beauty and proportions. It is difficult for 
the experienced chemist, to whom the technicalities of the sci- 
ence are familiar as the most common terms, to bear in mind 
thai to the beginner, they are as the words of an unknown tongue ; 
and that it is not principles alone that he must be taught, but the 
very language in which these principles are to be expressed. The 
remark has often been made by experienced teachers, that they 
had probably never taught any particular branch so well, as when 
learning it themselves; they were then most sensible of the diffi- 
culties which the beginner must encounter, and best able to assist 
him in overcoming them. A scientific professor once said to a 
lady, in a sarcastic tone — * and so you are going to attempt to teach 
Chemistry .' ' Yes,' said she, good naturedly, ' as fast as I can 
learn it myself.' The same professor was, afterwards, engaged 
to lecture and perform experiments before the lady's class, but 
her pupils complained that his language was so little adapted to 
their attainments, that they could neither understand his lectures 
or experiments, until explained to them in the familiar language 
of their teacher. 

A brilliant course of experiments is often of as little use to the 
beginner as would have been the sight of an exhibition of fire- 
works, or the ascension of a balloon. They show, indeed, the 
skill and knowledge of the experimenter, but rather confuse than 
assist the ignorant pupil. Thus it is that many a college student 
graduates, without having profited by the elaborate and elegant 
lectures with which he may have been favoured, because he was 
ignorant of the language and first principles of the science. 
These should have been acquired before. Professors in colleges 
and universities ought not to be expected to devote their time to 
teaching the a b c of Chemistry; those can do this as well, who 
have not made the attainments they have done, and who are not 
therefore as capable of being useful in the higher walks of 
science. We trust no learned Professor will be provoked to say 
to us, in the spirit of the gentleman just quoted — ' and so you have 
attempted to write a book on Chemistry ; ' for we humbly acknowl- 



IV PREFACE. 

edge that all we have aspired to, is to prepare those who may be 
privileged to attend upon his instructions to understand them, 
without subjecting him to the necessity of explaining first prin- 
ciples. 

There is another class, too, and that probably the most numer- 
ous, whom we have had in view in the preparation of this work ; 
it is those pupils who may not have future opportunities to pursue 
the study, except as they are led to make researches by private 
reading and observation. To give such a taste for chemical pur- 
suits, (without expecting in this little volume to make them chem- 
ists,) has been the writer's aim; and especially has she wished to 
manifest to the young, that every step in the science throws new 
light upon the economy of nature, and the wisdom of its great 
Author. 

The engravings in this book are in some cases from original 
designs, but are mostly copied from the works of Hare and Silli- 
man, with the consent of these gentlemen. Besides the impor- 
tant aid of these works, the author has availed herself of assis- 
tance from Webster's Chemistry, and has derived valuable hints 
from Eaton's Chemical Instructor. To Professor Hare she feels 
greatly obliged for his polite and encouraging attentions in for- 
warding to her some recent publications of his own, containing 
drawings of newly invented and highly useful apparatus. 

Mont Cervus, Guilford, Vt. July, 1834. 



TO TEACHERS. 

It is desirable that teachers should be able to make some experiments, let them 
be ever so simple ; but some who use this book, will probably be so situated as to 
render it very difficult. They must hear lessons in the bustle of the school room ; 
and have neither space nor time for experiments. In view of this, I have endeav- 
oured to make the work plain and simple, and to give such drawings as might 
compensate, as far as possible, for the want of experiments. Where the classes 
who use this book can hear lectures ; the order of the subjects should be varied to 
suit that of the lecturer. If your pupils are to hear a lecture on affinity, it would be 
well that they should previously study upon this subject, and afterwards be exam- 
ined upon the matter of the lecture as well as the book. In the Female Seminary, 
at Troy, where for several years, I had the charge of the chemical department, the 
pupils were required to perform experiments, and to give lectures before the class. 
on given subjects. In our public examinations each one had her subject assigned 
her, and was assisted with suitable books, that she might read and investigate for 
herself. The labour of thus directing them to search for principles, facts, and il- 
lustrations, was indeed, in some cases, greater than to have written the lecture ; 
but it was often richly rewarded by its beneficial effect on the mind of the pupil. 
From a paper before me containing an arrangement of subjects for these lectures 
of the pupils in 1829, the following is extracted as an example of the method : 

Subjects. 

Miss " " Applications of Chemistry to domestic enconomy. 

Miss " " Applications of Chemistry to medicine. 

Miss " '* Supporters of combustion. 

Miss " " Combustible substances. 

Miss " " Oxygen. 

Miss '" " Charcoal. 

Miss " " Chemical principles involved in the making of bread. 

Should this little volume lighten in some degree the arduous task of teachers, and 
assist them in imparting to their pupils a desire for knowledge, the author will 
feel that she has not laboured in vain. 



CONTENTS. 



CHAPTER L 

Introduction.— Of the Nature and Importance of Chemistry. 1 

CHAPTER II. 

Different kinds of Attraction. Explanation of Terms. Sim- 
ple Affinity. Elective Affinity. Double Elective Affinity. 13 

CHAPTER III. 

Chemical Affinity. Definite Proportions. Laws of Affinity. 25 

CHAPTER IV. 

Matter. Light — its Effects — its Laws of Motion. Rays of 
Light. Colour. 30 

CHAPTER V. 
Heat, or Caloric. 37 

CHAPTER VI. 

Thermometers. Conductors of Caloric. Evaporation. 46 

CHAPTER VII. 

Radiation of Caloric. Reflection and Absorption of Caloric. 
Freezing. Boiling. Sources of Heat. 59 

CHAPTER VIII. 
Electricity. Galvanism. Magnetism. 76 

CHAPTER IX. 

Alphabet of Chemistry? Gases. Mode of collecting Gases. 
Oxygen. 88 

CHAPTER X. 

Nitrogen. Atmosphere. Nitric Acid. Law of Definite Pro- 
portions. Nitrous Acid. Nitric Oxide. Nitrous Oxide. 100 



VI CONTENTS. 

CHAPTER XI. 

Hydrogen — its Properties — its agency in producing Earth- 
quakes and Volcanoes. Water. The Compound Blowpipe. 114 

CHAPTER XII. 

Sulphur. Combination of Sulphur with Oxygen. Selenium. 130 

CHAPTER XIII. 

Phosphorus. Impositions practiced by means of Phosphorus. 
Eudiometer of Phosphorus. Phosphorus and Oxygen. 
Phosphorus and Hydrogen. 139 

CHAPTER XIV. 

Carbon. Carbonic Acid. Carbonic Oxide. 146 

CHAPTER XV. 

Boron. Iodine. Fluorine. Bromine. 159 

CHAPTER XVI. 

Muriatic Acid. Chlorine. 169 

CHAPTER XVII. 
Ammonia. Gas Lights. Carburetted Hydrogen. 179 

CHAPTER XVIII. 
Sulphuretted Hydrogen. Cyanogen. Prussic Acid. 191 

CHAPTER XIX. 

Metalloids. Alkaline Metals. 197 

CHAPTER XX. 

Metalloids, or Earthy Metals. 206 

CHAPTER XXI. 
Metals. 212 

CHAPTER XXII. 

Oxides. Chlorides. Salts. 230 

CHAPTER XXIII. 

Organic Chemistry. Vegetable Chemistry. Vegetable Al- 
kalies. Oils, &c. 

CHAPTER XXIV. 

Organic Chemistry. Animal Chemistry. 261 



CHAPTER I . 



INTRODUCTION. 

Of the Nature and Importance of Chemistry. 

To you, who are now commencing the study ol 
Chemistry, it may be proper to give some reasons whj 
this is deemed a Science worthy of your attention: — 
the object of this introductory chapter will be, to ex- 
plain what Chemistry is, and why it should be studied 
by young persons. 

The knowledge of any science is desirable, because 
knowledge is in itself good, and it tends to make man- 
kind better, as well as happier. 

The time has been, that knowledge was confined to 
a very few, who were regarded by the ignorant world 
around them with superstitious dread, and who ruled 
over the minds of their fellow beings with the most 
despotic sway: indeed it was thought that men must be 
kept in ignorance in order that they might be governed. 

It is now found to be the case, that the most enlight- 
ened people are the most willing to submit to such laws 
as are necessary for the public good; so in every 
school, we find the best and wisest pupils most willing 
to submit to the rules. Since, therefore, knowledge 

What is the object of the introductory chapter 7 
Why is knowledge desirable '\ 
Has knowledge always been made common 1 
Why is it our duty to learn 1 
1 



8 CHEMISTRY FOR BEGINNERS. 

makes us better members of a community arid happier 
in ourselves, it seems our duty to learn. We live too 
in a world that God has made, and as his children, we 
should desire a knowledge of his works. 

If you should go into a work shop containing many 
curious things, you would be likely to ask, what those 
things were made of and how they were put together. 

Wherever you look around, you behold GoaV s work- 
manship;; and should you not like to know, what the ob- 
jects in nature are made of, and how they are put to- 
gether? This knowledge is called Chemistry. 

But, perhaps, you will be ready to ask, ' since Zool- 
ogy tells us about animals, Botany about plants, and 
Mineralogy about minerals, what is there left in nature 
for Chemistry to explain ? ' 

These sciences, indeed, teach you how to class ani- 
mals, vegetables and minerals, according to their out- 
ward appearances, but Chemistry shows you what 
they are made of and how they are put together. 

Here is a piece of salt, (I mean of that kind which 
is used with our food, for there are many other kinds of 
salt, as Chemistry will teach you ;) this being a min- 
eral substance, it is of course classed among such by 
the mineralogist ; perhaps by the shape of its crystals, 
or some other external circumstance. 

The chemist examines salt by a method which 
he calls analysis, and he finds that it is made or con- 



What inquiries should you be likely to make if you were to go 
into a workshop ? 

What knowledge is called Chemistry ? 

How does Chemistry differ from Zoology, Botany, and Min- 
eralogy 1 

By what circumstances would a mineralogist class salt ? 

Why would a chemist call salt muriate of soda ? 



NATURE OF THE STUDY. ¥ 

sists of an acid, called muriatic, and an alkali, called 
soda, and therefore he calls salt muriate of soda* 

By another method called synthesis, the chemist 
proves his analysis to have been correct ; that is, he 
puts muriatic acid and soda together, and finds that the 
result of this union is common salt. 

Here is a piece of chalk ; the chemist is able, by 
means of his analysis, to obtain from this a kind of air, 
called carbonic acid gas, and a solid substance called 
lime ; thus he calls chalk carbonate of lime. By syn- 
thesis or bringing lime water into contact with carbonic 
acid gas, a solid substance is gradually formed, by the 
union of the lime and gas, and this substance is car- 
bonate of lime, or chalk. 

Having endeavoured to explain, in a familiar manner, 
what Chemistry is, we will now give you a more con- 
cise definition of it ;— ' Chemistry teaches us to exam- 
ine the elements of substances, and their laws of com- 
bination' - 

The beginner in this study must not expect at once 
to understand all the terms which will be used ; for in- 
stance ' the elements of substances' cannot be compre- 
hended by one ignorant of the science, and ' their laws 
of combination ' will appear still less intelligible. 

* We are upon the threshold of the science met by a difficulty ; 
since common salt is of late generally considered as a chloride of 
sodium, in the strictest language of the science. But it will be 
understood that we are attempting to divest it of technicalities as 
much as possible, and we must therefore use such terms as are 
most generally received, without attempting to reconcile opposing" 
theories. 



How can the chemist prove the truth of his analysis 1 

By what two methods does the chemist prove that chalk is a 
cabonate of lime? 

Give a concise definition of Chemistry. 

Is the beginner expected to understand all the terms which 
may be used in explanation 1 



10 CHEMISTRY FOR BEGINNERS. 

But patient application to study will in time be re- 
warded by a gradual enlightening of the mind, so that 
many things which at first may appear dark will seem 
as clear and simple as the most familiar operations. 

We have remarked how Chemistry differs from 
Natural History, as the three sciences, Zoology, Bot- 
any and Mineralogy are called, we will now consider 
how it differs from Natural Philosophy. The latter 
science treats of the action of large bodies upon each 
other, as the attraction of the earth and the planetary 
bodies ; it shows what are the laws of motion, and the 
'principles which regulate and govern mechanical oper- 
ations ; while Chemistry, entering within the various 
substances formed by art or existing in nature, shows 
us their internal structure and composition. 

Natural History, Natural Philosophy and Chemistry 
are all necessary in order to give a complete view of 
objects ; the first explains their outward appearance ; 
the second their mechanical properties ; and the third 
their constitution. 

There is no science so intimately connected with the 
very life of man as Chemistry. Almost all kinds of 
cooking depend on chemical principles ; as also the 
preparation of medicine, the detection of poisons, the 
arts of bleaching, and pottery, of making glass, ink, 
and leather, of dyeing, burning lime, working metals, 
&c. The invention of the steam engine is owing to 
an application of chemical principles. 

A science connected with so many kinds of business 
cannot but be highly interesting to all, especially the 

What will be the effect of patient application to study ? 

How does Chemistry differ from Natural Philosophy 7 

What are the different provinces of Natural History, Natural 
Philosophy, and Chemistry? 

Why is Chemistry a useful science, and what are some of the 
arts which depend upon its principles and discoveries ? 

Why is a knowledge of this science important to all, and es- 
pecially to be recommended to the young- ? 



IMPORTANCE OF THE STUDY. 11 

young, who know not what their future condition in 
life may be, or what occasion they may have for va- 
rious kinds of knowledge. 

In most of the mechanical arts, and in some of the 
professions, those who understand Chemistry, have a 
great advantage over those who do not ; and in the 
cultivation of the earth, this science has also its impor- 
tant uses, since it teaches the farmer how to analyze 
different kinds of soil, and what is best fitted for par- 
ticular kinds of crops, 

' This science bears an important relation to house- 
keeping in a variety of ways, as in the making of grav- 
ies, soups, jellies and preserves, bread, butter and cheese, 
in the washing of clothes, making soap, and the econo- 
my of heat in cooking, and warming rooms ; — to fe- 
males then, some knowledge of Chemistry must be very 
desirable. They may indeed learn to perform these 
operations without understanding any thing of their 
philosophy; but it is natural to the human mind to seek 
to understand the causes of things, and it is by study- 
ing into them that improvements are made. 

We are not to suppose that the domestic arts have 
yet arrived to that perfection of which they are ca- 
pable ; for as chemists are not house-keepers, and house- 
keepers have not been chemists, there has been little 
opportunity for the study of domestic economy in its 
relation to Chemistry. 

Young ladies who attend to this study should there- 
fore pay strict attention to all those facts in house- 
keeping which may be explained upon chemical 
principles, such as the action of yeast upon flour, and 



What relation does Chemistry bear to house-keeping* 1 
Why have the domestic arts not yet received great improve- 
ment from Chemistry 1 

What should young* ladies who study Chemistry pay particular 
attention to 7 

1* 



12 CHEMISTRY FOR BEGINNERS. 

o[ pearlash upon sour dough, the change of cider into 
vinegar, the advantage of keeping a vessel covered in 
order to hasten the boiling of water, &c ; they should, 
in short, endeavour to make a practical application of 
their knowledge to the business of life. 

It should be considered by every young person that 
the object in studying Chemistry is not merely to ap- 
■ pear learned, and make a display by talking about ca- 
loric, oxygen, &c, but in reality to become wiser, and 
better fitted for usefulness in the world. 

There is one view in which the science of Chemistry 
produces in the mind thoughts of a deep and solemn 
kind, and calculated to humble the pride of man. 
When we learn that our own bodies, are composed 
of a few elements of the same nature as those 
which form the very worm that crawls, and that at 
death the union which subsisted between these ele- 
ments being dissolved, they will be separated and pass 
into the substance of the weeds that may spring up 
from their remains; we must fee] with him of old, 
who in his humiliation, exclaimed, ' I have said to cor- 
ruption, thou art my father and to the worm thou art 
my mother and my sister.'* 

But there is a portion of ourselves which is beyond 
the scope of chemical science, which cannot be 
analyzed, because it is incapable of being separated into 
parts. It is that within us which thinks and feels, 
which knows good from evil, which is destined to an 
immortal existence, and which at death passes from its 
prison of clay to the world of spirits. 

* Job XVII, 14. 



What should be the object of every young person who studies 
Chemistry ? 

In what view of the subject does Chemistry produce solemn 
reflections 1 

What portion of ourselves is beyond the scope of chemical 
science? 



ATTRACTION. 



All then that is done for the improvement of the mind 
either in knowledge or virtue, will be permanent, while 
the labour bestowed upon the care and decoration of 
the body will perish with that frail and decaying sub- 
stance. 



CHAPTER II. 



Different kinds of Attraction. Explanation of Terms. 
Simple Affinity. Elective Affinity. Double Elec- 
tive Affinity. 

Before proceeding to consider the substances which 
Chemistry examines, we shall investigate the operation 
of a power by which the simple elements of nature 
are combined and kept together, thus forming all the 
variety of objects which our earth presents. This 
power is called chemical attraction, or affinity. 

By the term attraction, in its most extended sense, 
is meant, the tendency of bodies to approach each 
other. 

Gravitation is that kind of attraction which exists 
between distant bodies ; it is this which causes a stone 
to fall to the earth. 

Cohesion is that kind of attraction which holds to- 
gether similar particles of bodies as in a lump of salt. 

Affinity or chemical attraction is that force which 
unites different substances into one compound substance, 

What reflection concludes this chapter ? 

Of what power are we now to investigate the operations ? 

What is meant by attraction in its most extended sense'? 

What is gravitation ? 

What is cohesion? 

What is affinity ? 



14 CHEMISTRY FOR BEGINNERS. 

thus salt is composed of muriatic acid and soda by 
chemical affinity. 

Besides these modes of attraction are reckoned those 
of Electricity and Magnetism ; although chemical af- 
finity may be occasioned by electricity, and magnetism 
is thought to be connected with it. 

The attraction of gravitation is the power which 
retains the planets in their orbits. This power is such, 
that if two bodies of equal size were placed at ever so 
great a distance from one another, and if there were 
no other bodies in the universe to attract them in diff- 
erent directions, they would rush towards one another 
and meet in a point equally distant from the one whence 
they started. The force of gravitation depends upon 
the size of a body and its distance; thus the smaller 
body will overcome the attraction of a larger one at a 
greater distance. The moon is smaller than the earth ; 
but supposing that body should advance very near to 
the earth so that a stone thrown upwards would ap- 
proach much nearer to the moon, the stone instead of 
falling downwards from the force of the earth's attrac- 
tion, would fly off to the moon.* k. leaden plummet 
suspended by a line from the top of a mountain is at- 
tracted towards its side, the nearness of the mountain 
overcoming the earth's attraction, which tends to draw 
it downward. 

* Several simple experiments maybe made to show the power of 
attraction, as 1. place two globules of mercury or quicksilver on 
a piece of dry glass, and push them slowly towards each other, 
when within a certain distance, they will rush tog-ether. 

2. If two pieces of cork or wood be placed in a dish of water 
near the centre, they will approach each other, with a rapidity of 
motion proportioned to their size. 



What other modes of attraction are there? 
Give a more particular account of the attraction of gravita- 
tion ? 



EXPLANATION OF TERMS. 15 

The attraction of cohesion differs from that of grav- 
itation, because it operates only upon small particles of 
bodies which are in contact. A piece of marble shows 
that it is composed of a collection of very small parti- 
cles ; these are held together by cohesion. This at- 
traction may be overcome by mechanical force, as 
pounding, grinding &c, but the elements of which 
marble is composed, that is carbonic acid and lime, can 
only be separated by means of chemical analysis, or 
by fire. 

Chemical attraction or affinity holds together the ele- 
ments of bodies. It is necessary to understand this 
subject in order to comprehend many of the changes 
which can be produced by means of chemical opera- 
tions. It is introduced in the beginning of your study 
that you may be prepared to comprehend what will 
follow. 

It is necessary here to make you acquainted with 
some terms of frequent use in Chemistry. A simple 
or elementary substance is one which cannot be sepa- 
rated or decomposed by any chemical process. 

These simple substances, or elements, are about fifty 
in number ; as you are yet unacquainted even with 
the names of many of them, it would be of little use 
to give them to you to learn ; after you shall have be- 
come somewhat acquainted with them, we shall wish 
you to understand how they are classed by chemists. 

A compound body is one which consists of two or 
more simple bodies or elements ; thus common salt is 
a compound body, consisting of soda and muriatic 
acid, which are united by means of chemical affinity. 

How does the attraction of cohesion differ from that of grav- 
itation 1 

Why should Chemical attraction be introduced in the com- 
mencement of the study ? 

What is a simple or elementary substance 7 

How many simple substances or elements are there ? 

What is a compound body 1 



16 CHEMISTRY FOR BEGINNERS. 

Deco??ipose — this means to separate the elements of 
compound bodies ; thus to break salt into pieces would 
not be to decompose it, but to separate it mechanically ; 
but in order to decompose salt, the elements must be 
disengaged from the union in which they are held. 

Analysis — this is a very important operation in 
chemistry, and consists in a separation of the parts of 
a substance in order to ascertain the elements which 
compose it. The methods of performing chemical 
analyses are various, and will be explained as we pro- 
ceed. Chemical analysis is performed by the decom- 
position of substances. 

Synthesis consists in forming a compound body by 
putting together two or more substances. 

The constituent parts of bodies may be ascertained 
either by analysis or synthesis ; thus water is found 
by analysis, or a disunion of its elements, to consist of 
two kinds of gas, and by bringing these two gasses 
together, water is formed. The correctness of the 
analysis is here proved by synthesis. 

You know the difference between a solid and a 
liquid — that is, the attraction of cohesion is less pow- 
erful in a liquid than in a solid; you can more easily 
penetrate water than wood. 

A gas is a substance in which the particles are still 
less governed by cohesive attraction ; the air, although 
it exists in the form of a gas, is not generally classed 
among gases, because it may be condensed by pressure 
or cold. When you burn sulphur, a yellowish vapour 
of a disagreeable odour, rises; this is sulphurous acid 

What is meant by decomposing a substance 1 
What is analysis'? 
What is synthesis 1 

By what two methods may the constituent parts of bodies'*/ 
ascertained ? 

W T hat is the difference between a solid and a liquid? 
What is a gas 1 



SIMPLE AFFINITY. 17 

sas. We shall hereafter consider the various kinds of 

o 

gases. 

There are two more terms which it is important you 
should understand : homogeneous means all of one 
kind; thus when salt is pounded, all the particles are 
found to be of the same nature. Cohesive attraction 
operates chiefly upon particles which are homogeneous. 
Heterogeneous means mixed; chemical affinity can 
only take place between heterogeneous particles ; it 
is generally the strongest between those substances 
which are the most unlike. 

There are three important particulars to be remem- 
bered respecting the nature of Chemical Affinity : — 
it is exerted at insensible distances ; between particles 
only ; and those, particles are always heterogeneous. 

SIMPLE AFFINITY. 

Simple Affinity is that force which causes the parti- 
cles of substances to unite, and produces a new com- 
pound. 

Experiment. — Take a wine glass containing a little 
water, and pour into it some sweet oil ; you will per- 
ceive they do not unite, but the oil floats upon the sur- 
face. Add a small bit of pearlash and stir the mixture. 
You now perceive that a union of the three substances 
is produced, and that a new compound, like soap is 
formed. 

Explanation. — Between water and oil there is no 
affinity, and therefore they remain without uniting; 



Define the terms homogeneous and heterogenous. 
What are three important particulars respecting- the nature of 
Chemical Affinity 1 

What is Simple Affinity 1 

What experiment illustrates Simple Affinity 1 

Give an explanation of the experiment. 



18 CHEMISTRY FOR BEGINNERS- 

pearlash having- an affinity for both, serves as a bond 
of union between them. 

Pearlash contains a large portion of potash, which 
belongs to a class of substances for which oil and fat 
of all kinds have a strong affinity. These substances 
are called by the general name of alkalies ; they in- 
clude lime, soda, potash, &c. We shall consider their 
nature as we advance in our study; at present it may 
be sufficient to observe that they have a peculiar acrid 
taste, as you may have perceived in the ley made from 
ashes; that they change vegetable blue to a green colour, 
and have a strong affinity for acids, a class of substan- 
ces possessing very different properties from alkalies. 

Acids are of various kinds, and will be explained 
hereafter. You know what is meant by an acid taste 
like that of vinegar* of a lemon, &c. ; but there are 
many properties of acids which, without a knowledge 
of Chemistry, you would not become acquainted with. 

We have shown you, by the experiment with water* 
oil, and pearlash, an instance of simple affinity. The 
making of soap is conducted on exactly the same 
principles as is here illustrated. 

Every economical family save all the bits of fat 
which are unfit for cooking in order to use for 
making soap. The ashes which are collected daily 
from the fire places and stoves are saved for the 
same purpose. When the soap is to be made, the 
ashes are put into a large cask called a leach and wet 
with water until they are saturated, that is, until they 
have taken up as much water as they will contain; 
after this, w T ater being added gradually, the ley runs off 
from holes near the bottom of the leach. This ley 



What is said of alkalies % 

What is said of acids 1 

By what chemical operation does the making" of soap depend ? 

Describe the process of making- soap as practiced in families 1 



ELECTIVE AFFINITY. 19 

contains the strength of the ashes, which besides some 
other substances abound in potash ; it is therefore high- 
ly alkaline. The materials which have been collected 
for the purpose, usually called soap-grease, are then 
thrown into a large iron kettle with the ley where 
they are boiled together.* A chemical union takes 
place between the alkali and the grease, and soap is the 
new compound which results from this combination. 

By throwing the grease into cold ley, soap will 
gradually be formed. This is called by house-keepers 
cold soap ; but heat causes the action of affinity to be 
more rapid, and for this reason most chemical opera- 
tions are performed by the aid of heat. 

Hard soap is made with soda instead of potash. The 
finer kinds of hard soap are made of olive or sweet 
oil, water, and soda. 

The volatile liniment so useful for burns and sore- 
throats, is made of ammonia, (hartshorn,) sweet oil, 
and water. 

ELECTIVE AFFINITY. 

The force of affinity is different between different 
bodies. 

Elective affinity signifies that preference which one 
substance has for another, by which a third substance 
is excluded. 

* In cities, and large villages it is generally thought more 
economical to dispose of the ashes and grease to the soap manu- 
facturer and receive soap in return. In the country, it is neces- 
sary for every family to make their own soap. 



How is cold soap made ? 

How is hard soap made ? 

How is volatile liniment made ? 

Is the force of affinity equal between all bodies ? 

What does elective affinity signify ? 

2 



20 CHEMISTRY FOR BEGINNERS. 

Experiment. — Pour a few spoonfuls of camphor 
which has been previously dissolved in spirits, into a 
tumbler, add a small portion of water, and the cam- 
phor will collect in little scales. It is then said to be 
precipitated. 

Eplanation. — The camphor and spirits were united 
by the force of simple affinity, and formed a clear 
solution ; on adding the water, the spirits having a 
stronger affinity for that, than for the camphor, united ' 
with it and excluded the camphor which again ap- 
pears as a white and solid substance. 

In the next experiment, we shall speak of sulphuric 
acid ; * as it is a substance of great importance in 
many chemical operations, it may be well to tell you 
that its common name is oil of vitriol, and that it is 
made by the union of sulphur with a gas called oxygen, 
with which you will soon be made acquainted. 
The union of sulphur and oxygen is an instance of 
simple affinity. 

We shall also in our next experiment speak 
of muriatic acid gas. This will be a new term, 
but it is impossible, let us begin where we will in 
Chemistry, not to be obliged to introduce terms that 

* Those pupils who are provided with a Dictionary of Chemis- 
try will do well to refer to it when any new substance is named. 
It is impossible to explain every term, while we attempt to 
proceed systematically in the developement of the science, as 
this must be continually taking- us from the main path. The use 
of a Dictionary of terms renders such irregularity unnecessary. 
No systematic work can be sufficiently full in explanation to pre- 
clude the importance of having at hand a Dictionary. 

By what experiment with camphor and water is elective affin- 
ity shown 1 

How is it explained ? 

What is said of sulphuric acid ? 

What is said respecting the use of new terms before their expla- 
nations 1 



ELECTIVE AFFINITY. 



21 



cannot at first be familiar to the beginner. We shall 
now propose to you another method of illustrating 
elective affinity. 



Put into a wine glass a 
teaspoon full of fine salt, 
and pour upon it the same 
quantity of sulphuric acid. 
You will see a wbite va- 
pour rise from the mixture, 
and will perceive that the 
substance in the wine glass 
is of a different nature 
from either of those which 
were used for the experi- 
ment. 



Explanatio?i. — Common salt is a compound sub- 
stance consisting of soda and muriatic acid. The 
soda having a greater affinity for the new acid which 
is added, elects it, and excludes the muriatic acid, 
which escapes in the form of a gas. This occasioned 
the vapour which appeared to rise from the glass. But 
the muriatic acid gas would be invisible, except that it 
has a strong affinity for water, of which there is always 
more or less in the air; uniting to particles of water it 
forms a little cloud. 

The substance which remains in the glass is the soda 
united to its new friend the sulphuric acid ; this is 
called sulphate of soda, it is the same substance which 
is so common in medicine under the name of Glauber' 1 s 




What experiment may : beTmade with salt and sulphuric acid 1 

Explain this experiment. 

What is the substance remaining in the glass 1 



22 CHEMISTRY FOR BEGINNERS. 

Salts, so called from the person who first added it to 
the list of medicinal articles. 

Experiment. — Into a solution of liquid muriate of 
lime let. fall a few drops of sulphuric acid. The muri- 
ate of lime will be decomposed, a sulphate of lime will 
be formed, and the muriatic acid will be set free, and 
pass off in the state of a gas. 

Explanation.— The lime has a greater affinity for 
sulphuric acid than for muriatic, it therefore elects 
the former, and the latter is excluded. 
- It is by means of elective affinity, that the chemist 
is able to decompose substances which otherwise could 
never be separated. For you perceive that chemical 
decomposition is quite different from mechanical sepa- 
ration. By no other means than elective affinity, could 
the muriatic acid and soda which compose salt, be sep- 
arated; for let the salt be pounded or ground into the 
smallest possible particles, every particle w T ould con- 
sist of muriatic acid and soda. 

DOUBLE ELECTIVE AFFINITY. 

. There is still another form of affinity, more won- 
derful in its effects than those we have already consid- 
ered. This is called double elective affinity, for by its 
means tvw compounds, each consisting of two ingredi- 
ents, are decomposed, forming two new compounds. 

In many cases one single compound consisting of 
two ingredients cannot be decomposed by any single 
element, as sulphate of soda cannot be decomposed by 
lime, because sulphuric acid attracts soda more strong- 
ly than it does lime. 

What experiment may be performed with muriate of lime and 
sulphuric acid 7 

Why does the lime unite with sulphuric acid 1 

Could the elements which compose salt be separated in any 
other way than by elective affinity % 

What is double elective affinity 1 

Can the sulphate of soda be decomposed by lime ? 



DOUBLE ELECTIVE AFFINITY. 



23 



Neither can the sulphate of soda be decomposed by 
muriatic acid, because the sulphuric acid attracts soda 
more strongly than the muriatic acid does. 

But though neither lime, or muriatic acid singly can 
decompose the sulphate of soda, the muriate of lime 
which is a compound of both, will effect this. 

Experiment. — Take muriate of lime and of the sul- 
phate of soda, and dissolve them in separate tumblers, 
then mix them and a solid substance, the sulphate of 
lime, will settle at the bottom of the glass, while a 
solution of the muriate of soda will be above it. 

Explanation. — Although neither muriatic acid or 
lime singly could separate the two substances which 
compose the sulphate of soda, yet by their mutual ac- 
tion at the same instant they cause the suphuric acid 
to unite itself to the lime, and the soda to the muriatic 
acid ; thus there is a mutual exchange of partners. 
Lime is attracted strongly by sulphuric acid, soda is 
attracted by muriatic acid, and thus as if by general 
consent the old connexions are broken up and new ones 
formed. 

The following figure may show the process more 
fully; the horizontal lines show the substances before 
mixture, and the diagonal lines after mixture. 

1st. Muriatic acid and Lime, formed 

Muriate of Lime. 




1st. Sulphuric acid 



and 



Soda, formed Sul- 
phate of Soda. 



What will decompose the sulphate of soda 1 
Describe the experiment which proves this ? 
Explain this experiment 1 

2* 



24 CIIF.MISTRY FOR BEGINNERS. 

It may be difficult for the beginner to understand 
this complicated process ; should it perplex you it will 
be best to pass on to what you will the more easily 
comprehend ; and then when you take up this subject 
again it will seem more intelligible. 

We have in this chapter considered the nature of 
attraction in general, its different kinds, and especially 
the different kinds of chemical attraction or affinity ; 
these were simple, elective, and double elective. 

4 There are few compound substances in which the 
chemist has not been able to overcome the resistance of 
affinity. The means of doing this are various and often 
very complicated ; many forces may be made to act 
upon a substance which seldom effectually resists when 
the decomposing forces are judiciously employed. 

' All the processes which may be resorted to in the 
treatment of different substances can only be known by 
a knowledge of the action which bodies exercise upon 
each other, of the changes which accompany this action, 
and of the compounds which result from it ; it is this 
knowledge which constitutes Chemistry.'* 

* Dictionary of Chemistry. 



Can it be decomposed by muriatic acid 1 

How does the figure show the process of double decomposition 1 
Is this subject easy to be understood by the beginner 7 
What have we in this chapter considered 7 

Are there many compound substances which the chemist has 
been unable to decompose % 

What knowledge is said to constitute Chemistry 1 



CHEMISTRY FOUNDED ON AFFINITY. 25 



CHAPTER III. 

Chemical Affinity. Definite Proportions. Laws of 
Affinity. 



As the subject of chemical affinity is one which the 
student should well understand, we will devote a little 
more time to the consideration of some of its phenom- 
ena. 

By phenomena you are to understand changes and 
appearances. Because it seems a hard word, you may 
suppose it difficult to be understood, but it is a conven- 
ient term to express an idea which otherwise would re- 
quire several words. By the phenomena of chemical 
affinity, we mean those changes which it produces on 
bodies, and the appearances which accompany these 
changes. 

We have seen by the experiments in the foregoing 
chapter, that the change produced by chemical affinity 
is very great ; so much so, that it seems in many cases 
wholly to alter the nature of substances. 

Sulphuric acid and potash in a separate state are 
distinguished by qualities essentially different : potash 
is a solid alkali which on being added to blue vegeta- 
ble infusions changes their colour green. Sulphuric 
acid is a liquid which changes blue vegetable colours 
red. The two substances are also distinguished by 
their peculiarities of taste, and their different action on 
other bodies. 

But let us add sulphuric acid to potash, in small 
quantities at a time, we shall at length attain a certain 

What is meant by the expression the phenomena of chemical 
affinity 1 

What is said of the change often produced by chemical affinity % 
What is said of sulphuric acid and potash in a separate state ? 
What change takes place by putting them together 1 



26 CHEMISTRY 10R BEGINNERS. 

point, at which the compound will exhibit neither acid 
or alkaline properties, having a bitter taste, and pro- 
ducing no effect on blue vegetable colours. 

In the case of the chemical union between sulphu- 
ric acid and potash, we see two of the most powerful 
and corrosive substances with which we are acquainted, 
producing a third which may be handled or swallowed 
without danger. This third substance is sulphate 
of potash, ranked in Chemistry among the salts, an im- 
portant class of substances formed by the union of 
acids and alkalies. 

When opposing properties are thus destroyed by 
chemical combination, the two substances are said to 
saturate each other, and the exact point at which this 
change is accomplished is called saturation. 

Experiment. — Put into two wine glasses half a tea 
spoon of muriatic acid to each — weigh in delicate 
scales two equal parts of carbonate of soda, about a 
teaspoon full to each glass ; put gradually small quan- 
tities of these parcels into the two glasses of acid ; 
at first there will be a violent action accompanied by 
a hissing noise, this is called effervescence, and it will 
cease when the acid is saturated, or has taken up all 
the alkali with which it will unite. On weighing what, 
remains of the carbonate of soda, you will find the two* 
portions equal, that is if you have been careful to stop* 
putting it in to the glass at the exact point when the* 
effervesence ceased in each. On examining thecon- 
tents of the wine glasses you will find them to be at 
solution of common salt. 

'Explanation. — Carbonate of soda is composed of 
carbonic acid and soda — but soda has a stronger affin- 

What is sulphate of potash ? 
What is meant by saturation 1 

Describe the experiment with muriatic acid and the carbonate 
of soda ? 

Explain the changes which take place in this experiment. 



DEFINITE PROPORTIONS. 27 

ity for muriatic acid than for carbonic, it therefore 
unites with the former and expels the latter, forming 
the muriate of soda (common salt.) The efferves- 
cence was caused by the escape of the carbonic acid 
gas. 

But what we are chiefly to illustrate by this experi- 
ment is the law of definite proportions, viz. that when 
two substances have united up to a certain point which 
nature has fixed, there can no longer be any combina- 
tion between them. Should you continue to drop into 
the acid, pieces of the carbonate of soda after it had re- 
ceived its definite proportion, there would be no union, 
but the carbonate of soda would fall to the bottom of 
the glass and remain unchanged in its nature. 

Water will unite with common salt until it becomes 
incapable of dissolving more. In making brine for 
salting meat, (especially pork which requires a strong 
brine in order to preserve it as long as that article is 
usually kept in families) it is best always to have a 
quantity of salt at the bottom of the barrel, which will 
always be the case when more is put into the water 
than that can contain. No brine can be stronger than 
that in which the water is saturated with salt, but 
the salt remaining at the bottom is a proof that this is 
the case. 

In the instance of brine, the common salt or muriate 
of soda does hot (as in the last experiment was the case 
with the carbonate of soda,) change its nature by part- 
ing with one of its elements, but unites with water, 
without suffering any decomposition. But in the 
one case there is a great change of properties, and in- 

What is this experiment chieflj^ intended to illustrate 1 
Is there a point beyond which water will not unite with com- 
mon salt 1 

Does common salt or muriate of soda change its nature by 
its union with water, as the carbonate of soda does in the ex- 
periment % 



28 CHEMISTRY FOR BEGINNERS. 

deed the formation of an entirely new substance, while 
in the other, the qualities which belonged to the origi- 
nal substances remain in part the same ; that is, the 
taste and other properties of brine are like that of salt. 

In the case of the carbonate of soda and muriatic 
acid, a violent action was occasioned by the new com- 
bination, but in the union of common salt with water, 
as nothing is excluded, the operation goes on in a quiet 
manner unattended by any remarkable phenomena. 

By affinity some substances unite in indefinite pro- 
portions, while their properties are not essentially al- 
tered. 

If you mix sulphuric acid and water, or alcohol 
and water, their properties will remain the same, al- 
though the particles being diffused among the water 
there will be less in a given space. 

We will now consider some of the most important 
laws* of chemical affinity, as from the explanations al- 
ready given you will probably be able to understand 
them. 

1. Affinity takes place only between bodies of a dif- 
ferent nature, as between an acid and an alkali, the at- 
traction between particles of a similar nature being 
that of cohesion, or, as it is sometimes called, of ag- 
gregation. 

2. Affijiity takes place only betv^een the most minute 
particles of bodies; therefore the more minutely sub- 
stances are divided by pounding, grinding, or by solu- 
tion, the more readily they act upon each other; thus 

*The complicated nature of chemical equivalents is not here dis- 
cussed as it might perplex the beginner at the commencement of 
his course. 

Are the phenomena in both cases the same 1 
Do some substances unite in indefinite proportion '{ 
What examples of this can you give ? 
What is the first law of chemical affinity 1 
What is the second law of chemical affinity. 



LAWS OF AFFINITY. 20 

if a lump of sulphur is thrown into alcohol no action 
will take place, but if sulphur be finely divided the bod- 
ies unite and form a transparent solution. 

3. The union produced by affinity is permanent and 
cannot be destroyed by mechanical means ; solutions of 
salt and sugar are not decomposed by standing for any 
length of time, but a mixture of powdered chalk or coal 
having no affinity, would in time exhibit a separation, 
the solid part settling at the bottom and the water ap- 
pearing clear. 

4. Bodies having no affinity are sometimes brought 
to unite by a third body ; thus an alkali unites oil and 
water. 

5. The force of affinity is different between different 
bodies ; this was illustrated in the decomposition of 
common salt by sulphuric acid ; where the affinity for 
soda was found to be greater for sulphuric than for 
muriatic acid. 

6. A change of temperature often takes place at the 
moment of combination ; this is very apparent in the 
case of adding sulphuric acid to water, when the heat 
becomes so great that it is impossible to hold the 
glass containing the mixture in the|hand. 

We shall not dwell longer upon the subject of chem- 
ical attraction, although as we proceed we shall have 
frequent occasion to refer to it for the explanation of 
many chemical changes. Cohesive attraction, the at- 
traction of Gravitation, of Magnetism, and Electricity, 
are subjects which belong more especially to the de- 
partment of Natural Philosophy, though as Electricity 
is supposed to have an important influence on chemical 
phenomena, we shall hereafter pay some attention to it. 

What is the third law of chemical affinity 7 
What is the fourth law of chemical affinity % 
What is the fifth law of chemical affinity 1 
What is the sixth law of chemical affinity 1 
What kinds of attraction belong- to the department of natural 
philosophy 1 



30 CHEMISTRY FOR BEGINNERS. 



CHAPTER IV. 

Matter. Light — its Effects — its laws of Motion. 
Rays of Light. Colour. 

We are now prepared to commence an examination 
of matter, since we have considered that great law 
which chemically unites or brings together the elements 
out of which are formed the various natural and arti- 
ficial substances which exist upon the earth. 

What is matter ? It is something which possesses 
qualities that are in some way manifested to our sen- 
ses. Your book is matter, so is your table, the trees 
and stones, the bodies of animals and your own body * 
all these are solid matter. The water and all kinds of 
liquids are another kind of matter. 

Is the air matter ? When you look from the place 
you now sit, across the room, you see some space which 
seems to be empty, but it is not so in reality, it is filled 
with air ; move your hand rapidly, and you will feel the 
air ; its motion will be attended with a sensation of cool- 
ness. What you can discern by any one of your sen- 
ses is matter. Feeling or touch is a sense ; air is 
perceived by it, therefore air is matter. It is a gas. 

Matter exists in three forms, that of a solid, a liquid 
and a gas. 

There are substances which chemists consider to be 
matter that appear under a form different in many re- 

What preparation have we made towards commencing- at ex- 
amination of matter % 

Give some account of matter ? 

How do you know that air is matter 1 

Under how many forms does matter exist 7 

Are there substances which do not come under any of these 
classes, that are considered to be matter, and how are they man- 
ifested to us % 



MATTER. 31 

spects from our ideas of material substances ; these are 
light and heat, electricity and magnetism ; they are 
manifested to us only as they act upon other substan- 
ces. 

Light is not what we see, but it is that, which, by 
falling upon other substances, and then coming to us, 
seems to tell us of their existence. If you enter a 
room in the dark you do not perceive what furniture it 
contains, but enter the same apartment in the light of 
day, and your eyes at once inform your mind of the 
existence of chairs, tables, carpets, &c. 

The picture made upon the eye is the effect of light. 
Its touch is very gentle, so much so that unless the 
light is very strong, it gives no pain to that delicate 
organ the eye ; but unless it touch the eye, how can 
it form an image there of the furniture of a room, of 
the landscape abroad and the expanse of the heavens ? 

Light is a most wonderful agent, and the organ on 
which it produces its effect is no less wonderful. 
When you look upon the heavens in a clear star-light 
and behold its countless millions of suns and worlds, 
separated as they are from each other by distances be- 
yond the power of numbers to compute, you see all 
this in a picture not more than an inch in diameter. 
Your eye does not go to the stars to learn their places 
and arrangement, but light travelling in every di- 
rection comes to your eyes and imprints there, that 
which your minds contemplates. So that it is not the 
heavens which you actually see, but a picture of them 
upon that part of the eye called the retina. 

Do we see light, or is it merely an agent to reveal other sub- 
stances to us 1 

What produces the picture upon the eye when images are 
there formed of external objects ? 

When we look abroad, do we see objects themselves, or pictures, 
of them 1, 

3 



32 CHEMISTRY FOR BEGINNERS. 

The study of the phenomena of light, as it is con- 
nected with sight or vision belongs to Natural Philos- 
ophy, and is called optics. 

Light, however, as one of the substances in nature, 
and as causing some chemical changes claims the no- 
tice of the student in Chemistry. 

Although light is classed among material substan- 
ces, it cannot be weighed, because neither our balances 
or organs of sense are sufficiently delicate. It is 
therefore called imponderable* 

Light proceeds directly from the sun and the fixed 
stars, and from the moon and the planets by reflection ; 
this is called celestial light ; it also accompanies heat 
in fire and in other cases of chemical combination, 
and this is called terrestrial light. We say other 
cases of combination because fire itself, or the com- 
bustion which produces it, is supposed to be caused by 
chemical affinity! 

Light moves with astonishing velocity ; it is compu- 
ted that it travels at the rate of two hundred thousand 
miles in a second. A ray of light is supposed to pass 
from the sun to the earth in about seven minutes. 

Light moves in right lines, never in curves ; when 
turned at all out of its course, it is always at an angle. 

* The word pondus in Latin signifies weight, from whence 
comes ponderable having* weight and imponderable having 
no weight. 

t Combustion, by some of the most distinguished chemists of 
the present day is supposed to depend on the union of opposite 
electricities, the oxygen of the air furnishing the negative and 
the combustible substance the positive electricity. 

What is the study of the phenomena of light as connected 
with seeing, called % 

Why is light considered is connected with Chemistry 1 

Why is it called imponderable ? 

What are the sources of light, and what are its different kinds 
called 1 

What is said of the velocity of the motion of light 1 

In what lines does light move 1 



LIGHT. 



33 



When light falls upon polished surfaces it is thrown 
back, or reflected. A person standing directly before 
a mirror sees his image as if it were fronting him, but 
if he stand a little on one side, his image will appear 
just as far upon the other. 

The rays falling from the person upon the mirror 
are called incident rays, those which are thrown back 
are called reflected rays ; the angles which they make 
are always equal. Thus two persons at opposite an- 
gles of a plane or flat mirror, see each other's images, 
although they cannot see their own. 

Nothing can appear less like a compound substance 
than a ray of light, and yet it is found to consist of 
seven colors, which are separated by means of a prism. 



A prism is a triangu- 
lar piece of glass some- 
times, as in the figure, 
supported on a frame 
for more convenient use, 
though the glass simply 
may answer all necessa- 
ry purposes. 



The prism should be used by placing it before a 
hole in a window shutter, the room being dark except 
by means of the light received through the aperture 




What effect is produced when light falls upon polished sur- 
faces 1 

What are incident and what reflected rays 1 

Is light a compound substance 1 

What is a prism ] 

What effect has the prism upon light as it passes through it ? 



34 CHEMISTRY FOR BEGINNERS. 

in the shutter ;— the light in its passage through the 
prism is separated into red, orange, green, blue, indigo, 
and violet. 

The red ray is the least refrangible that is, it is the 
least turned out of its course, and the violet is the 
most refrangible ; these different rays will be seen ar- 
ranged in the order in which they have been named 
upon any substance placed in a proper direction before 
the prism. 

The red ray is found to possess the most and the 
violet ray the least heat of the seven primary colors. 

You may see in a rain-bow exactly the same effect 
produced by the separation of the rays of light as that 
exhibited by the prism. The drops of water or falling 
rain, through which the sun's rays pass, act as the 
prism to break and reflect them according to their dif- 
ferent degrees of refrangibility. 

By mixing the seven primary colours in due propor- 
tions, white is produced. 

Colours are not in bodies themselves. The rose 
which you call red, is so made as to absorb all the 
other rays and reflect the red ray. The leaves absorb 
all except the green ray. In the dark, neither the rose 
or its leaves has any colour. 

White bodies reflect all the rays, black ones absorb 
all and therefore reflect none ; for this reason, white 
and black are not considered colours. 

It will at first appear to you a very strange idea 
that the colour of different substances is not in them- 

• Which ray is the most refrangible, and which the least so 1 
Do all the ray3 possess an equal degree of heat 1 
What produces the various colours of the rain-bow 1 
What is the effect of mixing the seven primary colours 1. 
Do colours belong to bodies, and and if not, how are they 
produced 1 

Why are white and black not considered as colours'? 
Is that colour which an object seems to have, the one for which 
its particles have an affinity 1 



COLOUR. 35 

selves but is caused by the manner in which they re- 
flect light to our eyes. We cannot explain why some 
bodies appear red, others green, &c. except by saying 
that it is because their particles have an affinity for the 
other rays of light, and reflects the red or green 
or whatever colour they may appear to us to have. For 
you must understand that the colour which an object ap- 
pears to have, is, in reality, that which it has not, or 
that which it rejects or throws off 

It follows from what has been said, that colour depends 
on the capacity which the particles of bodies possess 
of absorbing or reflecting the different rays of light. 

Experiment. — Soak in water some leaves of purple 
cabbage, the roots of radishes, or flowers of blue vio- 
lets, you then obtain a vegetable blue colour. Pour 
into this a few drops of sulphuric acid and the colour 
is changed to red. 

Explanation. — Since sulphuric acid is a colourless 
liquid, it cannot be that mixing it with the blue liquid, 
should change its colour in the same way that by putting 
red and yellow paint together you produce orange, an 
intermediate colour, which partakes of the nature of 
both. We infer then, that by the union of the blue in- 
fusion with the sulphuric acid, a new arrangement of 
the particles took place, which caused a different col- 
oured ray of light, viz, the red to be reflected, 

Thus by mixing solutions of corrosive sublimate and 
pearlash, both colourless substances, we are presented 
with an orange colour. By mixing a solution of 
pearlash with blue vegetable colours we have green. 
An infusion of nut galls mixed with one of copperas 

From what does it appear that colour depends on 1 

What effect according- to the experiment does sulphuric acid 
have upon a vegetable blue colour ^ 

How is this experiment explained 1 

Give some other examples of the changes which are produced 
Upon colours by the mixing of different stubstanccs 1 
3* 



36 CHEMISTRY FOR BEGINNERS,, 

produces black ; by pouring in a small proportion of 
sulphuric acid, tbe black changes to white ; that is 
from a state in which the particles reflected all the rays 
of light, they are thrown into one in which they ab- 
sorb all and reflect none. 

These are effects produced by chemical combina- 
tions. You can perceive then how important it is to 
those who mix colours either for dyeing or painting, to 
understand as far as possible, what may be done w T ith 
different substances in the way of producing variety 
and beauty of colours by means of such combinations] 

Light is contained in all bodies, though in many 
cases it remains in a state invisible to us. You have 
seen sparks of fire produced by two pieces of iron or 
other hard bodies being brought forcibly and suddenly 
in contact ; the fire was made manifest by means of 
the light w T hich accompanied it. 

Light and heat are not always connected ; the light 
of the moon called lunar* light is unaccompanied by 
heat. 

Some animals emit light, as the glowworm and sev- 
eral species of fire-fly. Those who sail upon salt wa- 
ter often observe a luminous path seeming to follow the 
vessel, this is owing to animal matter dissolved in sea 
water, or to collections of living animals so small 
and unformed as to exhibit no other appearance than 
a jelly like mass. Putrid fish, rotten w r ood and many 
other substances emit light. Phosphorus derives its 
name from this property. 

The importance of light to the growth of vegetables 

* From luna, the Moon. 



What is important for those who mix colours for dyeing- or 
painting 1 

Does light exist in any bodies in an invisible state ? 

Are light and heat always connected 1 

What is said of animal and other substances which emit light % 



CALORIC. 37 

is well known — if they grow at all in the dark, they 
usually exhibit a sickly appearance, and are destitute 
of colour and fragrance. 

Both plants and animals exposed to a strong light 
usually exhibit richer and more lively colours than 
those which live deprived of light, or where it is 
feeble ; thus, the birds, insects and flowers of the 
torrid zone surpass those of the other parts of the 
world, in the brilliancy and beauty of their colour. In 
the torrid zone only, are black people found, except 
it be among their descendants who have been carried 
to other parts of the globe. 



CHAPTER V. 

Heat or Caloric. 



We could not explain to one who had never felt the 
sensation of' heat what it is, any more than we could 
make a blind person understand the nature of colours, 
or a deaf one the nature of sounds. 

This is the case with all our sensations ; that of 
taste for example can be explained only by refer- 
ence to the sensation itself; there are various kinds of 
sweets, as that of honey, of sugar, and of many fruits 
which all differ from each other, in a manner which 
could never be explained to one who had not .tasted 
them. 



Do plants grow without light ^ 

Why are the animals and vegetables of the torrid zone, of a 
richer and deeper colour than in other portions of the earth *? 

Could we explain the sensation of heat to one who had never- 
experienced it 1 

Is this the case with all our sensations 1 



38 CHEMISTRY POR BEGINNERS, 

But the sensation or feeling- of heat is as different 
from the cause of heat, as the sensation we call sweet 
is from the sugar which produces it. 

"The feeling of heat is caused by a substance called 
caloric, from the Latin calor, heat. 

Caloric like light is an imponderable body, or one 
that has no known weight. 

Caloric and light are intimately connected; the one 
being generally acompanied by the other. But they are 
proved to be two distinct substances ; and as we have 
shown that light sometimes appears without caloric, we 
shall also find that caloric ma} r be perceived when 
there is no evidence of light. 

Iron may be made so hot that you cannot bear your 
hand upon it, and yet it will exhibit no light. Here 
is an instance of caloric without light. 

Caloric and light may be distinguished by the dif- 
ferent sensations they produce. Light is only perceiv- 
ed by the eyes, it produces vision or sight. Caloric 
may be perceived by its effects on every part of our 
body, which is one general organ of touch : the sensa- 
sation it produces is that of heat- 

Caloric exists in two different states free and com- 
bined. 

Free caloric comprehends all the sources of heat 
which are manifest to our senses as that which comes 
from the sun, from the fire and from heated bodies. 

Combined caloric exists in a cor cealed state in all 



Does the feeling" of heat resemble its cause 'I 

What causes the feeling- of heat % 

Is caloric known to have weight 1 

Are caloric and light the same substance 1 

Give an example of caloric existing without light. 

How may caloric and light be distinguished] 

In what different states does caloric exist? 

What is meant by free caloric 1 

How does combined caloric exist 1 



CALORIC. 39 

bodies. It is called latent or hidden caloric, and in 
this form exists even in ice itself. 

You will doubtless find it somewhat difficult to be- 
lieve that to be a real existence which has never been 
seen : but yet that something which causes heat, which 
produces flame, and which is active in the vegetable 
and animal creation has never been seen by us; its 
effects are around us on every side, but it is itself in- 
visible. 

Light and caloric seem to be in many respects the 
representatives and types of Him who created them 
and since we cannot deny that there is something 
which, though itself unseen, produces vision and re- 
veals to us the forms of bodies ; that there is some- 
thing which produces the sensation of heat which is 
also invisible, can we but acknowledge that there may 
be, around and about us, one great and pervading Spirit, 
the source, of mind, the Creator of matter and the di- 
rector of all things visible or invisible % 

When we speak of caloric, you will, therefore, under- 
stand that we mean a something which actually exists, 
and not a mere property or quality of matter ; — divisi- 
bility is a property of matter denoting that it is capable 
of being divided ; but divisibility is not itself a substance, 
any more than high or low, hard or soft are substances. 

Caloric passes from one substance to another ; it is 
only when in motion that we perceive its existence. 
When it is entering our bodies, we feel warm or hot : 
when it. is leaving them we feel cool or cold according 
to the degree of caloric we receive or lose. 

All our sense are affected by motion. 

Do we perceive caloric itself, or only its effects ? 
How do light and caloric represent their creator 1 
Do you consider caloric as an actual existence, or a mere prop- 
erty of matter 1 

When ig it that we perceive the existence of caloric 1 



40 CHEMISTRY FOR BEGINNERS. 

The motion of light produces vision. 

That of air hearing. 

That of odoriferous particles smelling. 

That of sapid substances tasting. 

That of bodies which touch us feeling". 

Since there is a something which produces heat, it 
would be natural to suppose that when this enters 
bodes it would increase their size ; this is found to be 
the case ; from whence this principle is established, 
that Caloric expands all bodies. 
Caloric expands solids. 



Experiment. — Take an iron rod a fitted in 
length to the space, Z>, and in diameter to pass 
through the circular aperture at c ; heat the 
rod to redness and it will be found too long to 
fill the one space, and too thick for the other. 
On cooling, the rod will again in length, and 
diameter, fill the same spaces as at first. 



Explanation. — The caloric which enters into the 
iron, crowds itself between the particles of metal and 
separates them at a little distance ; thus increasing the 
size of the rod. 



How are all our senses affected by motion 1 

Does caloric enlarge the size of bodies ? 

By what experiment is the expansion of solids illustrated 1 

How is this explained 1 



EXPANSIVE POWER OF CALORIC. 



41 



On putting- the heated rod into cold water, the caloric 
leaves it and passes into the colder substances and the 
rod is of the same dimensions as at first. It would 
cool in the common air, but not so soon as in cold 
water. 

An instrument called a pyrometer from the Greek 
pur, fire, and metron, measure, has been invented to 
show the degrees of expansibility of different metals by- 
heat. The figure shows a rod of metal, A A, resting 
horizontally upon supporters. 




One end of the rod touches the wheel work B, B, 
which is so connected with the index C, that a slight 
motion of the former, causes a considerable movement 
in the latter. The rod of metal, being heated by the 
lamps 1, 2, 3, presses against the wheel work which 
communicates motion to the index. The expansibility 
of the metal is denoted by the degrees marked on the 
plate. 



When the rod is again cooled, is its size affected i 
vvhat is a pyrometer 1 



42 CHEMISTRY FOR BEGINNERS. 

The pendulum of a clock is longer in warm than in 
cold weather : the vibration of the pendulum is quicker 
or slower in proportion to its length, or the longer the 
pendulum is, the slower the clock will go ; thus in very 
cold w r eather, clocks are liable to go too fast, on account 
of the contraction of the pendulums. 

A piano or harp that has been tuned in a cold room 
will often appear out of tune when the room is w r armed ; 
this is because the strings are expanded by heat. 

Glass stoppers sometimes get fitted into the necks of 
decanters so that it is difficult 'to take them out; if the 
bottle is plunged into hot water up to the neck, or a 
sponge containing hot water is applied to it the glass 
will expand and the stopper become loosened. 

The thinner any solid body is, the more readily it 
expands by heat ; thus, thin glass is not so liable to be 
cracked by hot water as that which is thick ; cut glass 
therefore is easily cracked 

The cause of the cracking of glass and china when 
put into hot water is their sudden expansion ; thus they 
are more liable to crack in cold than in warm weather, 
when the difference in the temperature of the atmos- 
phere and that of the hot water is not so great. When 
a china tea-pot is used in cold weather, in ke- warm water 
should be put into it before boiling water. Glass tum- 
blers and china cups should not have boiling water 
poured upon them in frosty weather. 

Why does a clock sometimes go too fast in very cold weather 1 

Why does a piano or harp when tuned in a cold room, ap- 
pear out of tune when the room is warmed '? 

How can a glass stopper fitting* tight in the neck of a decanter 
be taken out '\ 

Why is thin glass less liable to be cracked by hot water than 
that which is thick ? 

Why does glass and china sometimes crack when put into hot 
water 7 



EXPANSION BY CALORIC. 



43 



Caloric expands liquids. 

Liquids expand more readily* than solids, as the cohe- 
sive attraction in the former class of bodies is less strong, 
and caloric can pass more freely among their particles. 
Some liquids are more expansive than others. 

Experiment. 
Fill two globular 
glass vessels as far 
as to 0, 0, the one 
with alcohol the 
other with water ; 
place under each a 
pan of burning 
charcoal. Both li- 
quids will rise into 
the necks of the bot- 
tles but the alcohol 
will rise higher 
than the water. — 
Thesame principle 
may be illustrated 
by immersing two 
glass bulbs, the one 
containing water and the other alcohol, into a vessel of 
hot water. 

Molasses, wines, and other fluids, being expanded by 
heat, the same quantity will occupy more space in sum- 
mer than in winter ; thus it is more economical to buy 
them in winter. 

Caloric expands gases. 

As the particles of gases are very little influenced 
by cohesive attraction, caloric easily insinuates itself 
among them. 




Why do liquids expand more readily than solids? 

What experiment shows that different liquids have different de- 
grees of expansibility ? 

Why is it more economical to buy liquids in winter than in 
summer? 

Why are gases much affected by caloric ? 
4 



44 



CHEMISTRY FOR BEGINNERS. 



When a fire is made in a stove or fire-place the air 
of the room immediately begins to grow warmer, it 
expands also and becomes lighter ; the warm air escapes 
in all directions through cracks in the doors, windows* 
&c, and cold air rushes in to supply its place. 

Children who are fond of roasting eggs learn that 
it is necessary to crack the shell slightly, or it will 
burst with an explosion ; this is in consequence of the 
expanding of the vapor within, which escapes when it 
can find vent : but if confined, bursts the shell by the ex- 
pansive power of heat. 

Another amusement in which children sometimes 
indulge, is that of blowing air into bladders and ob- 
serving the effect which heat has upon them — this is a 
chemical experiment. If a bladder be tied tight at the 
neck although it should contain so little air as scarcely 
to swell it, yet when held to^he fire it will expand until 
it bursts ; if withdrawn from the heat before that takes 
place and put into a cold situation, it contracts. The 
addition of caloric expanded the air, the loss of it re- 
duces its bulk. 

Experiment. — Let the tube of a glass 
bulb having in it a small quantity of wa- 
ter, be inverted in a vessel of water. Ap- 
ply the heat of a lamp to the bulb, caloric 
will pass into it and expand the air, and 
this forces the water down the tube. Re- 
move the lamp, and as trie air contracts, 
the w r ater rushes back into the bulb. 

Explanation. — When the tube was in- 
verted, the water by its gravity was forced 
downwards, and air took its place. Caloric 




What changes take place with respect to the air when a fire is 
made in a room % 

Why are the shells of eggs cracked, before they are put into a 
fire to roast 1 

What is the effect of heat upon bladders containing a small por- 
tion of air % 

By what experiment is the expansion of air shown 1 



EXPANSION OF AIR. 45 

being applied to the bulb, penetrated it and expanded the 
air so that the water was forced farther down the tube, as 
soon as the heat was withdrawn and caloric began to pass 
off into the atmosphere, the air contracted and made 
room for the water to return again. 

The- expansion of air is eight times greater than that 
of water, and that of water forty-five times greater than 
that of iron. 

We have learned that solids, liquids, and gases are 
expanded or enlarged in bulk by the addition of caloric, 
and that they shrink, or are condensed by the loss of 
caloric. 

There is one remarkable exception to this law of na- 
ture — water though it expands by heat until it becomes 
a mere vapor, which we call steam, does not condense 
by the loss of heat, beyond a certain point. On the con- 
trary, when water freezes, its bulk is found to be in- 
creased, as many a housewife has known to her sorrow, 
when she has found her earthen pitchers or glass tum- 
blers cracked, by being suffered to stand full of water, 
exposed to a freezing atmosphere. 

You can very easily satisfy yourselves that water 
expands in freezing, by filling with it a tin basin, 
and letting it stand exposed to the cold of a winter 
night : you will see the ice swelled out considerably 
above the surface of the basin. 

It appears a wonderful provision of the Almighty for 
the preservation of man and animals that water should 



How is this experiment explained 1 

How does the expansion of air compare with that of water, 
and that of water with that of iron 7 

What have you now learned respecting- solids, liquids, and 
gases *? 

What exception is there to this law of nature'? 

How can you learn that water expands in freezing'? 

What appears a wonderful provision of the Almighty for the 
preservation of man and animals 1 



46 CHEMISTRY FOR BEGINNERS 

be the only substance which does not continue to con- 
tract by the loss of heat. 

If this were the case, when ice began to be formed 
in seas, lakes, and rivers, it would sink to the bottom, 
and by its coldness hasten the freezing of the upper 
portions of water until the whole mass would be one 
solid body of ice. The fish must then all die. The 
heat of one summer would not be sufficient to melt such 
an immense quantity of ice ; and thus it would go on 
increasing from year to year, and extending farther and 
farther, until the very seas of the equator would present 
a solid mass of ice, and the influence of this upon the 
land would be so chilling as to destroy all animal and 
vegetable life. 

Such would be the case had not the Creator made 
this one exception to the general law. Ice is lighter 
than water ; indeed water begins to grow lighter a 
little before the freezing process commences ; thus the 
ice remains upon the surface, preserving the water below 
from the influence of the cold air, so that it is a comfortable 
abode for its vast multitudes of inhabitants. How won- 
derful are the ways of Providence i 



CHAPTER VI. 

Thermometers. Conductors of Caloric. Evaporation. 

We are now prepared to consider the principle on 
which the thermometer is made. It is probable that 
most who study this book know what a thermometer is, 



What would be the result if water continued to grow heavier 
by the loss of caloric through all degrees of temperature 1 
Why does ice remain upon the surface of the water 1 
What are we now prepared to consider! 



THE THERMOMETER. 



47 



Be 



and tbe uses for which the instrument is val- 
uable, but some may never have seen or 
examined one. The figure will show you 
a thermometer ; and we will endeavour to 
explain the principle on w T hich it is construct- 
ed. 

The w T ord thermometer is derived from 
the Greek, iherme, heat, and inelron, meas- 
ure. This instrument is used for measuring 
the degrees of heat. It consists of a hollow 
glass tube, having at one end a small bulb or 
hollow glass ball. The bulb and pare of the 
tube contain mercury, above the mercury- 
there is a vacuum, that is the tube is empty, 
it contains no air; this vacuum is caused when 
the thermometer is made, by boiling the 
mercury, and closing * the end of the tube. 
The mercury condenses on cooling, and thus 
leaves a vacuum in the tube. The rising of 
the mercury shows an increase of heat, its 
falling shows a diminution of heat, and the 
quantity which it rises or falls denotes the 
proportion of increase or diminution ; this 
is pointed out by the figures standing for degrees which 
are marked on the frame of the thermometer. 

The thermometer represented in the figure, and the 
one most commonly used in this country, is that of Fah- 
renheit, a German chemist. The o is called zero ; all 
degrees of cold below this, are said to be so many de- 
grees below zero. At thirty-two degrees (expressed 



* That is, it is hermetically sealed ; which means to close the 
end of a glass vessel while it is in a melted state. The term 
hermetic is derived from Hermes or Mercury, who was considered 
as the father of Chemistry. 



What is the thermometer used for 1 
Describe Fahrenheit's thermometer. 

4* 



48 CHEMISTRY FOR BEGINNERS. 

32°) water freezes. This is marked on the figure by 
F. Between 50° and 60° (see F on the figure,) is tem- 
perate. Summer heat (marked S. H.) is a little below 
80°. Blood heat (marked B. H.) is at 98°. Fever heat 
is 112°. Spirits boil at 176°. Water boils at 212°. 

If the bulb of the thermometer were plunged in boil- 
ing water, the mercury would rise to 212°; if plunged 
into melting snow or ice it would fall to 32°. What 
was said with respect to the expansion of bodies by heat, 
will help you to understand the cause of the rising and 
falling of the mercury in the thermometer. 

The thermometer is of great use not only to scien- 
tific men in their experiments, but for many common 
purposes. The apartments of the sick should always 
be of the same temperature ; and to regulate this, a 
thermometer is necessary. It is needed by gar- 
deners to regulate the temperature of their green- 
houses. It assists the navigator, informing him by 
means of the increased coldness of the water, when 
he is approaching land, soundings or shoals ; especial- 
ly warning him against the icebergs so common in north- 
ern latitudes; on the contrary when approaching the 
Gulf-Stream the water becomes warmer. 

There is another kind of thermometer, which we will 
now describe ; it is called an air thermometer, because 
it operates by means of the expansion of air. The fig- 
ure represents the air thermometer of Sanctorius an 
Italian physician, of the seventeenth century ; this w r as 
the first of the kind which was invented. The egg- 
shaped vessel with a long neck is called a matrass ; this 
is supported, with its neck downwards, by a ring and an 
upright wire ; the tube is open and extends below the 



What effect do boiling" water and ice have upon the thermom- 
eter 1 

What are some of the practical uses of the thermometer ^ 
Describe the air thermometer. 



THERMOMETERS. 



49 




surface of the water into 
the cup beneath. On hold- 
ing any heated substance 
near the matrass, the air 
being expanded, a portion 
of it escapes through the 
water of the cup ; on re- 
moving the heat, the air 
condensing in the matrass, 
receives water into the neck 
to replace the air which 
escaped. Now when heat 
is afterwards applied, the 
air which remains in the 
bulbous part of the mat- 
rass, in expanding, forces 
the water lower down in 
the neck. If ice were applied, the air condensing would 
admit a still greater portion of water into the matrass. 
Air thermometers are useful in determining those 
slight differences of temperature, which would 
not materially affect the mercurial thermometer ; 
for you will recollect that as gases are more ex- 
pansible than any other bodies, air will be sooner 
affected by heat than mercury. 

There is another kind of air thermometer which 
is generally preferred to that of Sanctorius ; this is 
shown by the figure. It consists of a glass bottle 
containing a small quantity of coloured water; 
the bottle is closely corked, so that the air with- 
in cannot escape ; a very small glass tube is fitted 
into the cork, and extends down so as to pass into 
the fluid. On applying heat, the air in the bottle 
being expanded, presses upon the liquid beneath it 
and forces a portion up the tube. The height of 



For what are air thermometers useful *? 
What does the figure represent 1 



50 



CHEMISTRY FOR BEGINNERS- 



o 



the fluid shows the expansion of the air, or the degree 
of heat to which the air thermometer has been sub- 
jected. 

There is still another kind of 
thermometer ; it is called the dif- 
ferential thermometer, because its 
use is to determine the difference 
of temperature in any two bodies 
or places. It has two bulbs, as 
you see in the figure ; its tube is 
partly filled with some coloured 
liquid while the remainder is filled 
with air. When both bulbs are 
exposed to an equal temperature, 
the fluid in the tube remains un- 
moved, but if one bulb is exposed 
to more heat than the other, the fluid will rise towards 
the opposite bulb* This is on account of the expansion of 
the air, which, pressing upon the liquid, causes it to re- 
move. 

The barometer is used for ascertaining the weight 
of the atmosphere* the mercury in that instrument 
rises w r hen the pressure of the air is greatest, and falls 
when it is least- never lower than about twenty seven 
inches, nor higher than about thirty three inches. A 
column of air forty-five miles high, is supposed to be of 
equal weight to a column of mercury thirty inches 
high, and a column of water thirty three feet high. 




CONDUCTORS OF HEAT OR OF CALORIC. 

Caloric has a constant tendency to pass from one 
body to another, that is to go from a substance contain- 
ing more, to one that has less, until both shall be of an 



Describe the differential thermometer. 

For what is the barometer used, and on what principle does the 
mercury in that instrument rise? 

What is remarked of the tendency of caloric to produce an 
equilibrium 1 



CONDUCTORS OF CALORIC. 51 

equal temperature, or as chemists would say, until an 
equilibrium between the two is produced. 

Suppose that one person having very cold hands takes 
the warm hand of another person — you can imagine 
the very different sensations which each would exper- 
ience. The one says, 'how cold your hand is,' the 
other, ■ how warm.' Caloric leaves the warm hand to 
go to the colder one which comes in contact with it; 
this causes the sensation of cold to the person who loses 
caloric, while the one who gains it, feels the sensation of 
warmth. 

But let a healthy person having a warm hand take 
the burning hand of one in a fever, and the latter will 
seem hot, while to the sick person, the hand of the other 
will appear cool. 

If the door of a warm apartment be opened into a 
colder one, the warm air rushes out, and the cold enters, 
until the two apartments are of an equal temperature. 

Some substances conduct heat much more readily than 
others. 

Experiment. — Take a pipe-stem and an iron wire of 
equal size and length, and stick to one end of each, 
balls of bees wax, of equal size: place these in such 
a situation that the ends opposite the wax will receive 
an equal degree of heat from burning coals. The wax 
on the iron rod will soon melt, while that on the pipe- 
stem will scarcely be affected by heat. 

Explanation. — Both rods receive caloric, which passes 
from one particle to another, but with much greater 
rapidity from the particles of iron than those of the clay. 

What takes place when one person, having 1 cold hands, takes 
the warm hand of another \ 

How does the hand of a person in a fever appear to the warm 
hand of a healthy person 1 

What is the effect of opening" the door of a warm room into a 
cold one 1 

Do all substances conduct heat in the same manner ? 

What experiment shows the difference in substances, as to their 
power of conducting- heat l 

Explain the experiment. 



52 



CHEMISTRY FOR BEGINLNERS. 



Take four small rods, metal, wood, 
glass, and whalebone, and cement 
one end of each to a ball of sealing 
wax ; then let the opposite ends 
be equally exposed to heat ; the 
metal will soon become so hot as 
to melt the sealing wax, the wood 
and whalebone will burn near the 
wax without melting it, and the glass 
may be heated so that it may be bent, 
without affecting the wax. 

If you hold one end of a pin or 
needle in the flame of a candle, 
it almost instantly becomes so much 
heated at the other end as to burn 
the fingers. A glass rod of equal 
size may be held in the same situa- 
tion, until the end in the flame melts with heat, and yet 
the other end seem little affected by it. 

Such substances as feel coldest to the touch, are gen- 
erally the best conductors, while those that in their or- 
dinary state feel warmest are the poorest conductors. 
Thus metals are good conductors, while feathers, wool 
and hair are poor conductors. 

Bodies conduct heat with less facility when their 
parts are spongy and divided ; thus iron filings are 
poorer conductors than an iron bar of the same weight ; 
this is supposed to be owing to the existence of air be- 
tween these parts, and air is a poor conductor. 




What is the second experiment for illustrating" the principle 
we are now considering" 1 

What different effects would you perceive on holding one end 
of a knitting" needle, and one end of a g-lass rod of the same size 
in the flame of a candle 7 

What substances are g-enerally the best and what the poorest 
conductors ? 

Why are iron nling-s a poorer conductor of heat than an irou 
karl 



CONDUCTORS OF CALORIC. 53 

Stones are not as good conductors of caloric as met- 
als — bricks are poor conductors, and for this reason 
when heated and wrapped in a cloth, they are useful 
for keeping the feet warm in cold weather ; but a heated 
piece of plank is still better, because wood conducts or 
loses caloric less easily than brick. 

Wool, hair, and fur, are poor conductors of ca- 
loric. Thus we find that the animals of cold coun- 
tries are protected against the severities of their cli- 
mate by their covering. These are not warm in them- 
selves but they keep the animal heat from escaping into 
the cold atmosphere. 

We speak of particular garments being warm, but 
this is incorrect; the less readily substances conduct 
heat, the warmer they keep our bodies by preventing 
their caloric from passing off. The looser the materi- 
als of which garments are made, the warmer they 
will be ; thus quilted under garments containing a 
slight quantity of cotton, are much warmer than the 
same weight of a cloth of firmer texture. Our good 
grandmothers used to labor hard to manufacture thick 
and heavy woollen blankets and coverlets; but we 
have learned that two thicknesses of calico, quilted with a 
few pounds of cotton between, make a bed-covering much 
warmer, lighter, and cheaper than the carpet-like blan- 
kets of former days. 

The finer the fibres of substances are, the less do 
they serve as conductors of caloric ; thus the animals 
of cold countries are furnished by their Creator with 
finer and softer feathers, wool, and fur, than those of 
warm countries ; indeed if the latter animals are car- 
ried to frigid regions, He who gave them their cover- 

What is said of stones and bricks as couductors of caloric 7 

Of what use are the wool and fur of animals in cold countries 1 

Are some garments really warmer than others, and if not, why 

are our bodies warmer when clad with them than others ? 

Why is it that the animals of cold countries are furnished witli 

softer feathers, wool, and fur, than in hot countries 1 



54 



CHEMISTRY FOR BEGINNERS. 



ing, makes it to grow softer and finer that they may 
be protected from the cold. 

Ice and snow are bad conductors of caloric ; thus 
the ice in rivers and lakes protects the water below 
from freezing ; snow is of great use in protecting veg- 
etation from frosts and severe cold. When the snow 
comes early in the season, and remains late, the farmer 
expects a good crop of grain, but when there is not snow 
to protect it, it is often winter killed. 

Liquids are not as good conductors of caloric as sol- 
ids ; in the latter the particles are fixed and transmit 
caloric from one to the other ; 
when liquids are heating, the 
particles themselves are in mo- 
tion, and carry caloric with 
them. 

When a kettle of water is 
placed over the fire, the par- 
ticles of the fluid at the bottom 
of the kettle first receive caloric, 
they expand, become lighter and 
rise to the top ; the colder par- 
ticles sink, and are in their turn 
heated and rise. This process 
continues until the whole is 
heated. The figure shows the 
heated parties rising and giv- 
ing place to colder ones. 

You will perceive, from the 
r manner in which water becomes 
heated, that if a vessel of this liquid were placed under 
instead of over the fire, the lower portions of the water 




Are ice and snow good conductors of caloric 1 ? 

What comparison is made between the conducting- powers of 
liquids and solids ? 

What process goes on when liquids are heated % 

What would be the effect of placing liquids under a fire instead 
of over it ? 



CURRENTS OF AIR. 



55 



would not be heated ; because the 
warm particles, being lighter, 
would still remain at the top. 

This principle may be illus- 
trated, as in the figure, by insert- 
ing into the bottom of a vessel of 
water an air thermometer, and 
burning ether or alcohol upon the 
surface of the water. The bulb 
of the thermometer, although with- 
in half an inch of the flame, will 
be unaffected by heat. 

Gases are the poorest of all con- 
ductors of caloric. 

The common air stops the pro- 
gress of caloric more than any oth- 
er substance. Why do people use 
a fan in warm weather ? Because* 
when the air is set in motion, the 
warmer particles are driven away,, 
and cooler ones take their place. 
These are pleasant and refresh- 
ing for the moment; but that they do not take away 
heat from us, is evident, from the fact, that the instant 
we cease to fan ourselves, we feel as warm as at first. 

If, instead of cool air, we had been bathed with cool 
water, we should have felt our bodies sensibly cooled. 

When air is heated, currents are produced. In a 
room where there is a fire, the air in the upper part is> 
warmer than that in the lower part, because the particle^ 
which are warmed instantly rise, are cooled as they 
ascend, and then fall again; thus in a warm room there 




What does the figure illustrate 1 
Are gases good conductors of caloric % 
What is the use of a fan in warm weather? 
What produces- currents of air? 



56 CHEMISTRY FOR BEGINNERS. 

is always an ascending and a descending current of air* 
If a door of a warm room be opened, hot air rushes 
out at the upper part, while cold air blows in below. 
This may be proved by holding the flame of a lamp at 
an open door; at the upper part, the flame will be blown 
outwardly, at the lower part inwardly, while midway, 
the flame will remain in its usual perpendicular posi- 
tion. 

You can now understand the causes of winds, which 
are only currents of air ; thus warm air being light- 
er rises upwards, while cold air, being heavier, presses 
downwards. In geography, you read of the monsoons 
of India ; or of winds which blow six months from 
the south, and six months from the north ; — the sun is 
six months in going from the equator to the northern 
tropic and returning ; during this time the surface of 
the earth north of the equator is heated ; the warm air 
rises, and cold air from the southern hemisphere rushes 
in to supply its place j this is a southerly monsoon j 
the northerly monsoon is in like manner produced when 
the sun is in the southern hemisphere. 

The constant circulation both in the air and waters of 
the globe, is of vast importance to the comfort of man. 
In this way the hot air of the equatorial regions, is 
tempered by winds from cooler countries, and the heated 
waters of one portion of the earth, mingle with the 
cooler currents from the other. 

EVAPORATION. 

When you leave a small quantity of water in a tea- 
saucer or any open vessel, in a short time you per- 
ceive the dish is dry. Did you ever think what be- 
comes of the liquid in this case ? It passes into the air 

What causes the monsoons of India ? 

How does the circulation in the air and waters of the globe 
tend to the comfort of man 1 

What do you understand by evaporation ? 



EVAPORATION. 57 

in fine particles called vapour ; thus we say it has 
evaporated. 

Caloric is the great agent in evaporation ; the warmer 
the weather is, the faster the process of evaporation is 
carried on. In very hot weather a floor that has been 
sprinkled with water will soon be dried, that is the water 
will have evaporated, and the air having parted with 
caloric will appear cooler. 

In cities during hot weather persons are employed to 
go about the streets with large casks of water, which, 
by an apparatus contrived for the purpose, is sprinkled 
over the path as the cart which contains it moves slowly 
along. This not only prevents the dust from rising, but 
has a very sensible effect upon the atmosphere around, 
from which the water in evaporating withdraws a portion 
of caloric. 

Physicians sometimes order persons sick with fevers 
to be wet with cold water, by means of a sponge ap- 
plied to the face, chest and limbs ; and cause this opera- 
tion to be performed very frequently with water taken 
fresh from a well. In a few minutes a bowl of water 
thus applied to a person in a high fever will become 
warm from the caloric which it has gained. Sueh a 
process as you might naturally suppose, has a tendency 
to abate the fever ; and though it may not remove the 
cause, it affords a temporary and refreshing alleviation. 

The air always contains more or less moisture, some 
degree of which seems necessary to our breathing: 
when the air is unusually dry, we feel as if our lungs 
were parched, and we desire to drink often. 

That the air contains moisture is shown by the ap- 
pearance of a tumbler of cold water in a hot day. It 

What is the great agent in evaporation ? 

Why are the streets in cities sprinkled with water during" the 
hot weather 1 

Why do physicians sometimes order their patients to be wet 
in cold water ? 

Does the moisture in the air seem necessary 7 

What shows that the air contains moisture 1 



fOR 



58 CHEMISTRY |.0R BEGINNERS. 

will be covered by moisture or even drops of liquid J 
this cannot proceed from within, since the water does 
not penetrate the glass ; it is caused by the condensing 
of the fine vapour of the air by means of the coldness 
of the tumbler. 

You must by this time, if you have studied with at- 
tention the subjects which this book has presented you 
w r ith, perceive that Chemistry is a vast science. It is 
now but in its infancy, and yet how many phenomena 
has it explained to the understanding of man, which 
were once either regarded with superstitious terror, or 
passed without observation! But we should neither 
superstitiously ascribe to miracles, changes which sci- 
ence can explain, or look with stupid indifference upon 
the operations of nature. 

Society is now rapidly improving, and inventions 
by means of scientific principles and discoveries are 
fast following each other. Much of the labour which 
was once performed by men, is now carried on by ma- 
chinery ; this gives more leisure for observations and 
experiments, w T hich are the only means of making far- 
ther discoveries. 

When we examine the names of those who have 
benefitted the world by their discoveries, we find that 
practical mechanicians, those who have at the same 
time worked and studied, have done as much, even for 
science, as those who have been wholly devoted to the 
learned professions. 



What do we perceive from the subjects already considered, 
with respect to the importance of Chemistry ? 

What gives opportunities for further observations and experi- 
ments in the sciences 1 

Who are those that have most benefitted the world by their 
discoveries 1 



RADIATION OF CALORIC, 



CHAPTER VII. 



Radiation of Caloric. Reflection and Absorption of 
Caloric. Freezing. Boiling. Sources of Heat. 

We have seen that caloric is conducted from one 
particle of a substance to another, and that bodies differ 
in their conducting power. We are now to consider 
caloric as passing directly from one body to another by 
means of a power which enables it to dart forward with- 
out assistance from any intermediate substance. This 
is called radiated heat, because it passes off in rays, in 
the same manner as light is radiated. 





A and B concave mirrors fixed on stands, c heated iron ball 
placed in the focus of the mirror A, d Thermometer in the focus 
of the mirror B. 1, 2, 3, 4 rays of caloric, radiating from the iron 
ball, and falling" on the mirror A. 5, 6, 7, 8 the same rays reflected 
from the mirror A to the mirror B. 9, 10, 11, 12 the same rays 
reflected from the mirror B to the thermometer. 

Experiment. — The figure represents two concave me- 
talic mirrors fixed on stands ; they are placed upon a 



What is meant by radiated caloric 1 
What experiment proves the radiation of caloric ? 
5* 



60 CHEMISTRY FOR BEGINNERS. 

table at the distance of a few feet, and directly oppo- 
site. Now if an iron ball be heated almost to redness, 
and placed in the focus* of one mirror, and an air ther- 
mometer be placed in the focus of the other mirror, the 
thermometer will be at once affected by the heat.f 

Explanation. — Caloric was radiated from the heated 
ball in every direction, the rays lessening in intensity 
according to their distance from the ball ; those rays 
which are intercepted by the mirror, are reflected back 
in right lines until reaching the other mirror, they are 
then reflected in a collected form upon the bulb of the 
air thermometer standing in its focus. The lines in 
the figure represent the course of the rays of caloric. 
* It is a property of concave mirrors to render parallel 
the divergent rays received from its focus ; and to cause 
the parallel rays which it intercepts to become converg- 
ent so as to meet in its focus? 

Surfaces which reflect light most perfectly, are not 
always best for the reflection of heat; a glass mirror 
placed before a heated ball would absorb the rays of 
caloric, and become warm itself, without reflecting the 
rays. Glasses are used to protect the eyes from the 
effects of intense heat during some chemical experiments. 

If, instead of a heated iron ball, a mass of ice were 
placed in the focus of one of the mirrors, the air ther- 

* By the focus is meant that point where all the reflected rays 
meet. 

1" In some books on Chemistry, an increase of temperature is 
said to be indicated by the falling of the air thermometer, in oth- 
ers by its rising 1 ; this is according as the thermometer of Sancto- 
rius, or the other one described, on the same page, is used. The 
same principle by a different mode of construction causing dif- 
ferent appearances. 

How do you explain this experiment 1 

Are surfaces which reflect light most perfectly, the best for the 
reflection of heat ? 

What would be the effect if a mass of ice were placed in the 
focus of one of the mirrors, and an air thermometer in the focus 
of the other ? 



RADIATION OF CALORIC. 



61 



mometer in the focus of the opposite mirror, would 
show a diminution of temperature, or that it had lost 
caloric. You might from this suppose that cold was 
radiated like caloric, but in this case the radiation is 
from the thermometer itself, which is the hotter body, 
and parts with some of its caloric to the ice. 

There is indeed no such thing as cold. Cold water 
contains caloric, the loss of a portion of which changes 
it to ice; ice contains caloric, for there are colder sub- 
stances than this, as freezing mixtures of various kinds. 
Cold is a term denoting the absence of heat. 

Polished or light coloured surfaces do not radiate heat 
as well as those which are rough and dark coloured. 

Experiment. — 
The figure repre- 
sents a square 
glass bottle placed 
opposite a concave 
metallic mirror. 
You are to sup- 
pose one side of 
the bottle to have 
been smoked with 
the flame of a 
lamp until com- 
pletely blackened, 
and another side covered with tin ; in the focus of the 
mirror is placed the bulb of a thermometer, having be- 
fore it a little circular screen, to prevent any rays of heat 
from the bottle falling directly upon the thermometer. 
The bottle being filled with boiling water, the different 
sides are successively turned towards the reflector ; the 
thermometer indicates the greatest increase of tempera- 
ture by the blackened side, and the least by the metallic 
side, while the effect of the glass side is greater than the 
one, and less than the other. 





Is cold a real existence % 

Do polished or light coloured surfaces reflect heat as well as 
those which arc rough and dark colored % 



62 CHEMISTRY FOR BEGINNERS. 

Explanation. — Rays of caloric from the bottle of hot 
water were thrown upon the mirror, which reflected 
them in a concentrated form upon the an thermometer 
placed in its focus. The blackened side parted with 
heat faster than the other sides, of course the thermom- 
eter denoted the greatest increase of caloric when that 
side was presented. The tinned side being bright and 
polished did not admit the rays of heat to pass freely 
through it, and thus w r hen that was presented, the ther- 
mometer showed a lower degree of caloric. The glass 
side transmitted heat better than the polished tin, but 
not so well as the blackened and rough side, of course 
it affected the thermometer more than the one and less 
than the other. 

An experiment illustrating the same principle may 
be performed in a more simple manner ; by holding a 
thermometer successively before the sides of a tin can- 
ister, one of which has been scratched and blackened 
with lamp smoke, and the other sides remain bright 
and smooth. The thermometer will be more affected 
by the direct rays of caloric, than in the other experi- 
ment by the reflected rays. 

The following statement shows the different propor- 
tions in which heat was radiated from a cubical tin 
vessel, one of whose sides was blackened, another pa- 
pered, and another glazed : 

The thermometer was raised by the 

blackened side 100 degrees 

papered " 98° 

glazed " 90° 

bright metallic " 12° 



What experiment may be made to show the different powers of 
different surfaces to reflect heat '? 

Explain the experiment. 

How may the same principle be illustrated in a more simple 
manner 1 

In what proportions are different surfaces found to radiate heat? 



REFLECTION OF CALORIC. 63 

Those bodies which absorb heat most readily, radiate 
it most powerfully, that is, their absorbing and radia- 
ting powers are equal ; a piece of iron heats soon, and 
parts with its heat readily; a brick neither heats as 
soon, or so quickly parts with caloric. 

Radiation and reflection are found to be in an in- 
verse proportion: that is, those bodies that radiate calor- 
ic most powerfully, reflect it least ; thus, the reflecting 
mirror did not radiate heat which came from its own 
substance, but threw back the rays which fell upon it, 
as a hard substance causes the rebounding- of a ball. 

Some colours absorb caloric more readily than others. 
This may be shown by a very simple experiment. 
Take a piece of black woollen cloth, and another of the 
same size and quality of white or light coloured, and 
lay them upon the snow, when the sun is shining. In 
a few hours the black will be found to have sunk 
considerably below the surface of the snow, while 
the white will remain on the surface. From this we 
infer, that the black cloth absorbed caloric from the 
sun and gave it off in sufficient quantity to melt the 
snow beneath, while the white did not absorb caloric. 
You will recollect that black bodies absorb all the rays 
of light, while white ones reflect them all. But in the 
case of caloric, black substances not only absorb but 
reflect it, while with respect to light it does not reflect 
any of its rays, 

FREEZING. 

We have already remarked, that there is in reality 
no such thing as cold; what we call cold being merely 
the absence of heat. When we put our hand upon a 

What bodies radiate heat most powerfully ? 
How do radiation and reflection differ? 

What is said of the difference in colours with respect to absorb- 
ing caloric % 

What causes a sensation of cold when we put our hand upon icel 



64 CHEMISTRY FOR BEGINNERS. 

piece of marble, or ice, we say ' it is cold ' — we feel 
what we call a sensation of cold; but the sensation is 
caused by the loss of caloric which our hand experien- 
ces on coming in contact with a colder substance. 
You will remember the property of caloric to produce 
an equilibrium, and that a body which contains more 
heat, always communicates it to another which has less, 
when the two are brought together. 

When solids become liquids, caloric is absorbed from 
surrounding bodies. You may easily prove this by 
putting your hand into a vessel of common salt and 
water; the salt, in dissolving, that is, in passing from 
a solid to a liquid state, absorbs caloric from the water 
and renders it so cold as to be painful to the hand. 

Ice-creams, which it was formerly thought could only 
be obtained at a confectioner's, may be easily prepared 
in any family by the following simple process : put the 
cream, suitably prepared with sugar, &c, into a tin vessel, 
with a tight cover, and place this in a larger pail or tub, 
surrounded with pounded ice and fine salt ; the edges of 
the cream will soon freeze ; a spoon should then be 
introduced into the vessel of cream and remove the 
frozen part into the centre, and in the course of a few 
hours the whole will be frozen. The process should 
be carried on in a cool room, and the vessel of ice kept 
covered, to protect it from the calorie of the air. 

You will scarcely need to have this experiment explain- 
ed, since you understand that solids in becoming liquids 
take caloric from surrounding bodies. Ice alone would 
make the cream very cold, but would not, in melting, 
take away sufficient caloric to freeze it ; but by adding 
another solid, viz. salt, which having a great affinity 

What is the effect upon surrounding bodies when solids btcome 
liquids 1 

How may ice-cream be prepared ? 

Why is ice alone not sufficient to freeze the cream ? 



FREEZING. 65 

for water, assists in bringing it into a liquid state, and 
is thus itself dissolved, more caloric is taken from the 
cream, so that its temperature is reduced below the 
freezing point ; of course it becomes solid. 

We have seen that solids in becoming liquids absorb 
caloric, and you must also have thought, from the ex- 
ample of the cream becoming ice in consequence of 
parting with caloric, that freezing is a process by which 
heat is given off; this is the case, freezing is a warm- 
ing process, and melting is a cooling process. 

Our winters would be much colder were it not for 
the freezing which is going on, and which, in changing 
liquids to solids, gives out caloric into the atmosphere. 

The cold, chilly winds that are so common in the 
spring in our climate, are caused by the melting of ice 
and snow. 

The caloric which exists in cold water is called la- 
tent, (from lateo, concealed,) because it is not percepti- 
ble to our senses. 

When liquids become solids, heat is given out. 

This may be illustrated by the slacking of lime, the 
water unites with the lime in a solid state, and much 
heat is pressed out ; buildings have taken fire from the 
circumstance of water having accidentally been brought 
in contact with lime. As more caloric is necessary to 
keep a body in a liquid than a solid state, you can per- 
ceive the reason for the fact stated. 

The same principle may also be illustrated, by adding 
to a small quantity of muriate of lime in a wine glass, a 
little sulphuric acid ; both the substances are liquid, 

What are the different effects of warming" and freezing* upon 
surrounding" bodies ? 

What prevents our winters from being" colder than they now are 1 

What causes the cold winds of spring 1 

What is said of the caloric which exists in cold water ? 

What takes place when liquids become solids 1 

How may this be illustrated 1 

In what other way may the same principle be illustrated ? 



66 



CHEMISTRY FOR BEGINNERS. 



but they unite and form a solid sulphate of lime ; so great 
a quantity of latent caloric is pressed out, that the glass 
becomes almost too hot to be held in the hand. 

As ice becomes water by gaining caloric, water be- 
comes steam or vapour by the same process. Put a 
piece of ice on a fire shovel and hold it over the fire, 
the addition of heat to the solid, soon changes it to a 
liquid ; continue to hold the shovel over the fire, and 
the liquid soon disappears ; it has gained sufficient- ca- 
loric to change it to steam. The steam, by losing ca- 
loric, is condensed and becomes water, and that by 
losing still more caloric becomes ice again. 

BOILING. 

When liquids are united to a certain degree of heat, 
they are converted into steam or vapour ; this process 
is usually attended with a bubbling noise and an agi- 
tation of the fluid, called boiling. 

We have shewn under ca- 
loric, (see page 54,) that when 
a kettle of water is placed 
over the fire, the heat soon 
causes particles of the fluid 
to rise by rendering them 
lighter, while, at the same, 
there is a descending current 
of the colder particles ; this 
process continues until the 
whole mass is heated to 212 
degrees ; a new operation 
then begins. The heated 
water at the bottom now re- 




How is ice affected by gaining" caloric, and how may steam be 
changed to ice '\ 

What is boiling % 

Describe the process which goes on when water is converted 
into steam. 



BOILING. 67 

ceives more caloric, and becomes steam, or vapour, 
which passes off into the atmosphere, as you see in the 
figure. The water in the kettle is not raised above the 
212°, but remains at this point until the very last drop 
has been changed to vapour. You will perceive by the 
figure, that the steam near the spout of the tea kettle is 
invisible, while it may be seen at a little distance; this 
is owing to its mixing with the cooler atmosphere which 
condenses it, and thus gives it the appearance of a cloud. 
Vapour or steam is of the same temperature with 
the boiling liquid so far as indicated. by the thermom- 
eter ; which stands at 212 in boiling water, and 
the same in the steam which issues from it ; but 
yet there exists in steam a much greater quantity of 
caloric, although in a latent state. As a large quantity 
of latent caloric is combined with water, a still greater 
portion is necessary to hold water in the gaseous state. 

A celebrated chemist computed the heat of steam in 
the following manner; he noted the time necessary to 
raise a certain quantity of water to the boiling point, 
or 2 L 2°; he then kept up the same heat until the 
whole was evaporated, and marked the time consumed 
by the process. Allowing the increase of heat to "con- 
tinue in the same ratio, he estimated that the steam 
contained 810° of latent heat, or that this quantity was 
necessary towards keeping water in a state of vapour j 
this, added to the 212° of heat apparent by the ther- 
mometer, would make the actual caloric existing in 
steam, 1022°. 

When steam is condensed, or when vapours return 
to their liquid state, their latent heat is rendered sensi- 
ble ; a small quantity of steam gives off a great por- 
tion of caloric. 

The powerful heat of steam is experienced by those 

Is there more caloric in steam than in boiling" water 7 
How did a celebrated chemist compute the heat of steam 1 
What takes place when steam is condensed 1 

6 



68 CHEMISTRY FOR BEGINNERS. 

who accidentally hold their hands for a moment near 
the spout of a boiling tea kettle. The pain which en- 
sues is very acute. Children have been known to die 
from inhaling into their lungs the least portion of 
steam, from the spout of a tea-pot of hot water. If 
such be the effects of the very least quantity of steam 
in contact with any portion of our limbs or our lungs, 
how awful must be the condition of those unfortunate 
persons, who, in the bursting of the boiler of a steam 
boat, are not only enveloped in an atmosphere of this 
powerful and dreadful vapour, but obliged at every 
breath to inhale it into their lungs 1 




This figure shows the manner in which steam causes 
explosions of steamboat boilers. You are to suppose 
the little glass bulb, suspended over the lamp, to con- 
tain a very small quantity of water, and to be hermeti- 
cally sealed. The heat of the lamp converts the water 
into steam, the expansive power of which is so great, 
that the glass bulb would soon burst with a violent ex- 
plosion, if the heat were continued. Had there been 

What is remarked of the powerful effects of the heat of steam 
in contact with our bodies 1 

What does the figure represent 1 



BOILING AFFECTED BY ATMOSPHERIC PRESSURE. 69 

any way of escape for the steam, it would have passed 
off without bursting the glass vessel. The boilers of 
steamboats are usually of copper, and furnished with a 
valve, which can be opened as occasion requires, for the 
purpose of letting off the steam. 

The degrees of steam are marked in such a way 
that the engineer can know what force is employed, 
and understanding the power of his steam engine, if 
he use due care, accidents will seldom happen, for 
when he finds the steam increasing too fast, he lets it 
off by means of the safety-valve. But should the en- 
gineer neglect this, and suffer more steam to be formed 
in the boiler than it can contain, you can at once per- 
ceive, by the experiment with the glass bulb, that the 
boiler must burst; for copper can no more resist the 
expansive power of steam than glass. 

The Effect of Atmospheric Pressure upon Boiling. 

We are surrounded on all sides by the atmosphere, 
or air ; it is supposed to be about 45 miles in height ; 
that is, that this distance on every side of our globe is 
occupied by this invisible and elastic substance. Thin 
and light as air is, yet it has weight ; and it has been 
proved that a column of air 45 miles high is equal in 
weight to a column of water thirty three feet high, and 
a column of mercury thirty inches high. 

As you will learn many particulars respecting this 
in Natural Philosophy, we shall only consider the 
weight or pressure of the air as it respects boiling of 
different substances. 

Although we are not sensible of the fact, yet the air 
is pressing upon us, and upon all bodies on the earth, 
at the rate of about fifteen pounds for every square inch. 

When liquids boil, steam in ascending has this 

How does the engineer of a steam boat know how much steam 
is produced % 

By what is our globe surrounded ? 
What are we now to consider with respect to the air 1 
What is said of the pressure of the air upon all bodies ? 
What has to be overcome when liquids boil 'I 



70 



CHEMISTRY FOR BEGINNERS. 



weight of the air to overcome. When the atmospheric 
pressure is less than common, water boils at less heat 
than 2! 2°, which is what is usually required. 

As we ascend mountains the pressure of the air is 
less. At Mont Blanc, and upon the Andes, water was 
made to boil at a heat of about 180°. It is said, that 
for every five hundred and thirty feet of elevation, the 
boiling point is lowered one degree of Fahrenheit's 
thermometer. 

Experiment. — The following* 
"is a curious illustration of the ef- 
Ifect of pressure in opposing the 
boiling process. You are to sup- 
pose a glass vessel half filled with 
water and closed perfectly tight, 
heated until it is entirely filled 
with steam; the boiling now ceas- 
es, but let the vessel be taken from 
the fire and apply a sponge wet 
with cold water, the liquid within 
begins to boil again. The process 
=may be repeated ; when the vessel 
?is over the fire, boiling will cease, 
and continue to be renewed upon 
the application of a cold substance. 
Explanation. — The vessel being filled with steam, 
its pressure prevented the farther boiling of the water. 
If it were to be kept for a short time in this situation, 
the increase of steam would burst the glass. On tak- 
ing the vessel from the fire, and applying the cold 
sponge, the steam was condensed, and the pressure 
being thus removed, the boiling began again. This 
experiment shows that a lower temperature or less 
heat is required for boiling liquids when the pressure 
of the atmosphere is taken off. 

What is said of the pressure of the air upon mountains 1 
What experiment illustrates the effect of atmospheric pressure 
in opposing the boiling" process 1 
Explain this experiment. 




SOURCES OF HEAT. 



'1 




The figure shows a vessel of 
water boiling under a glass ves* 
sel, called a bell-glass. You are 
to suppose the air has been all 
exhausted from the receiver by- 
means of an air pump. The wa- 
ter heated to boiling, being with- 
drawn from the fire, the boiling 
ceases ; on placing it under the 
exhausted receiver, the boiling 
again takes place, and will con- 
tinue for some time. 

The explanation of this phe- 
nomenon is the same as given for 
the last experiment, viz. the press- 
ure is removed ; in this case, it 
was that of the atmosphere ; in the experiment previ- 
ously described, the pressure removed was that of steam, 
which when condensed left a vacuum. 

If pressure be greater than that 
of the atmosphere, more than 
^212° of heat will be required to 
boil water. Suppose a matrass, 
partly filled with water, and 
placed over a lamp, as represented 
in the figure. If the mouth is 
closed with the thumb, the water, 
though heated to 212°, will not 
boil, but the vapour created, will 
press upwards until it becomes 
difficult to keep the thumb over 
it. On removing the matrass 
from the lamp, and lifting the 
thumb from its mouth, boiling 
This experiment 




gg? commences. 



What does the figure represent 1 

What is the explanation of the phenomenon here observed 1 
What will be the effect when there is a greater pressure than that 
of the atmosphere 1 

6* 



72 CHEMISTRY FOR BEGINNERS. 

shows that if the pressure of the atmosphere were 
greater than it is, a proportional increase of heat would 
be necessary in order to overcome this pressure suffi- 
ciently to boil liquids. 

SOURCES OF HEAT. 

The Sun is the great source of heat as well as of 
light. It radiates caloric in all directions ; these rays 
may be collected by mirrors of a peculiar kind. In 
the focus of these mirrors a powerful heat may be ob- 
tained, sufficient to inflame combustible substances. 

Combustion, or the burning of different materials, is 
the most important source of heat, next to the sun. It 
is by means of this that cooking of most kinds is per- 
formed, and that we are made warm and comfortable 
in winter, and are furnished with lights in its long 
evenings. 

Did you ever think as you looked at the fire, and 
felt the warmth from it, what it is which creates the 
heat ? Suppose that in a cold room some dry wood is 
laid in the fire place, and a spark of fire struck from 
a tinder box, makes a blaze ; very soon the fire burns 
brightly and you begin to feel warmth. Yet the wood 
was cold, every thing in the room was cold, but now 
there is warmth. 

We will explain this. By striking two pieces of flint 
violently together, caloric, which was latent in them, is 
brought into a free and active state ; this, meeting with the 
dry combustible substance, unites with it and produces 
flame. The air furnishes caloric which exists in it in a 



What is the great source of heat 1 
What is said of combustion 1 

What takes place when a fire is made in a cold room ^ 
How do you accouut for the wramth which is produced by 
combustion 1 




COMBUSTION. 73 

latent state, but is pressed out by the process of com- 
bustion, and becomes sensible warmth. 

That the air 
does contain la- 
tent heat may be 
proved by the use 
of a little instru- 
ment called a fire 
syringe, which is 
very convenient 
for lighting a fire. 
This consists of a small metallic tube, to which is 
fitted a rod and piston, as seen in the figure, A piece of 
tinder is fastened to the end of the piston ; the rod 
is forcibly pushed to the bottom of the tube, and the tin- 
der is set on fire. The tube was filled with air ; on 
being compressed by the sudden moving the piston, 
the particles of air were brought so closely in contact 
with each other, as to force out caloric. 

The flame which accompanies the burning of wood, 
oil, &c, is a subject about which chemists have enter- 
tained various opinions, and which seems still to be 
doubtful. 

-Combustion may proceed without flame ; this is the 
case when any substance burns without being exposed 
to the air. Thus the timbers of a house beneath a 
brick fire-place have been known to become so much 
heated as to burn to a coal without the fire being per- 
ceived ; had a column of air been admitted to the tim- 
bers thus consuming, a powerful flame must have been 
the consequence. 



How can it be proved that air contains latent heat ? 
Is it easy to account for the flame which accompanies the burn- 
ing" of wood, oil, &c. % 

Can combustion proceed without flame % 



74 



CHEMISTRY FOR BEGINNERS. 



Chemical affinity produces 
heat; this may be so great as 
to produce boiling*. The figure 
represents a longer tube con- 
taining coloured alcohol, placed 
within a shorter and larger 
tube ; the latter should contain 
water reaching about one fourth 
as high as the alcohol in the in- 
ner tube ; upon adding to the 
water about three times as much 
sulphuric acid, the alcohol will 
boil violently. Alcohol boils 
with less heat than water, but 
the experiment proves that a 
large portion of caloric is press- 
|ed out by the combination which 
took place between the water 
and sulphuric acid. 
The figure below shows an instance of combustion by 
means of chemical affinity. The larger vessel contains 
a deep plate holding a quantity of alcohol ; a very small 





By what experiment is it shown that chemical affinity produces 
heat 1 

What does this experiment prove 1 

What is the lower figure designed to represent 1 



OF ANIMAL HEAT- 75 

quantity of a solid substance called the dor ate of potash is 
placed in the midst of the alcohol, a little sulphuric acid 
being then poured upon it, the flame bursts forth. The 
glass containing the sulphuric acid is fastened to the end 
of a rod because there is some danger from the explosion 
which takes place. 

Besides the sun, combustion, and chemical affinity, 
there are other sources of caloric, as electricity, 
whose phenomena appear on a grand scale in a thun- 
der storm, percussion, or the violent striking of hard 
bodies against each other, and friction, or the rubbing 
of substances. 

By percussion, fire is struck from flint by steel, and 
carriage wheels, when in violent motion, strike fire 
from the stones in the path. 

By the friction of dry leaves, or other dry combust- 
ibles, the Indians are said to obtain fire in the forests. 

We have as yet said nothing of the cause of animal 
heat, for the subject is too difficult to be understood in 
this stage of your progress ; and, indeed, the greatest 
philosophers find much difficulty in understanding the 
wonderful operations, which are carried on in the com- 
plicated machinery of living bodies. Although chem- 
ists are able to learn the composition of salts, minerals, 
gases, &c, they yet remain ignorant of what constitutes 
the principle of life in a plant, an insect, or a man. 

Hitherto we have treated of subjects, which, from 
their nature, were somewhat abstruse, and, in some re- 
spects, calculated to confuse the mind. You will re- 
collect that affinity is not a substance, but a power ; and 
a power on which the science of Chemistry chiefly 
depends for its operations. Light and Caloric are sub- 



What other sources of caloric are there, besides those which 
have been mentioned ?- 

What is the effect of percussion 1 

How did the Indians obtain fire in the forests 1 

Is it easy to understand the causes which produce heat in an- 
imal bodies 1 

What general remarks conclude the chapter 7 



76 CHEMISTRY FOR BEGINNERS. 

stances; they are called imponderable, because they 
are too delicate to be weighed by any balances which 
we have; indeed we cannot perceive them by any of 
our senses, not even by that of sight. Light, like our 
eyes, enables us to see other bodies, although it is it- 
self invisible. Caloric is only visible by its effects ; 
the flame which we see is only produced by the union 
of caloric with a combustible substance, aided by some 
principle contained in the air. The heat which we 
feel is only the effect of caloric entering our bodies. 



CHAPTER VIII. 

Electricity. Galvanism. Magnetism. 

Electricity is an imponderable fluid, which we know 
only by its effects. 

The word was derived from the Greek, electron, sig- 
nifying amber, because it was in this substance that 
electricity, or a power of attracting light substances, was 
discovered. 

The electric fluid is supposed to be diffused through- 
out the earth as extensively as caloric ; and like caloric 
it seems to exist in a latent state, except when its equilib- 
rium is disturbed. 

You have probably observed on rubbing the back of a 
cat in the night, that sparks as if of fire appear, and you 
feel a prickling sensation in your hand. This is caused 
by electricity. Fur is one of those substances called 
non conductors of electricity, because instead of con- 

What is electricity ? 
What is the term derived from ? 
Is the electric fluid extensively diffused 1 

What causes the sparks which appear on rubbing the back of a 
cat in the anight 7 



EFFECTS OF ELECTRICITY. 77 

ducting off the electric fluid, it is capable of accumulating 
it, and becomes electrically excited. In this situation it 
gives off electricity, which is manifested by the sparks 
and the sensation it excites. 

Another familiar example of the effect of the electrical 
fluid may have been noticed by you. When taking off 
clothing of silk or woollen which has been worn near 
the skin, sparks are often seen to come from it accompa- 
nied by a snapping noise. The garment having col< 
lected electricity from the body, gives it off when exposed 
to the air. 

The hair often appears as if electrified, especially in 
cold weather ; this is manifested by its standing erect, 
and appearing to fly back when the hand is placed near it. 

But the grandest of all the appearances caused by 
electricity, is that which is witnessed in a thunder storm. 

The state of the atmosphere, from some cause un- 
known to man, becomes, at times, especially during hot 
and sultry weather, such as to disturb the equilibrium of 
the electric fluid ; — clouds are formed, some of which 
contain more electricity than others. When such clouds, 
containing different degrees of electricity, meet, the one 
which contains most, discharges the fluid. This dis- 
charge produces both the thunder and lightning; the 
latter is seen before the former is heard, because that 
light travels faster than sound. 

We are able to estimate the distance of thunder from 
us by the number of seconds which intervene between 
the flash and report. Light moves with such velocity 
that we make no calculation for any time which passes 
between the discharge of the electric fluid and the ap- 
pearance of the flash of lightning, but sound is supposed 

What other familiar example of the effect of electricity is 
mentioned % 

What do we sometimes observe with respect to the hair, espec- 
ially in cold weather 1 

What is the grandest exhibition of electricity ? 

What causes the discharge of the electric fluid in a storm 1 

How are we able to judge of the distance of thunder from us 1 



78 CHEMISTRY FOR BEGINNERS. 

to move nearly at the rate of a mile in a second ; there- 
fore the number of seconds that pass after the lightning 
is seen, before the thunder is heard, shews how many 
miles distant the storm is. When we can count twenty 
or thirty seconds between the lightning and thunder, w^e 
suppose the storm to be about as many miles distant from 
us. When the report follows the flash almost at the 
same moment, we may know that the storm is very near 
us ; and when persons are struck with lightning, the 
clouds bursting directly over their heads, the thunder 
and lightning appear at the same instant. 

CONDUCTORS AND NON-CONDUCTORS OF ELECTRICITY- 

It is of importance to learn what are conductors and 
what 7ion- conductors of electricity, that we may take 
proper care in thunder storms not to expose ourselves 
unnecessarily. The metals are conductors — for this 
reason it is unsafe during a thunder storm which is very- 
near, for people to wear spectacles with gold or silver 
bows, w r atches, thimbles, buckles in shoes, or indeed any 
metallic substance about the person — for when a house 
is struck with lightning, the electric fluid is usually 
conducted by the air down a chimney, or by the beams 
or walls into different apartments and will dart out of 
its way if a bright metallic substance offers itself as a 
conductor. 

Feathers and hair are non-conductors — for this reason 
a feather bed or mattress is a safe position in a thunder 
storm. A seat upon a sofa or chair drawn out from the 
wall, with both the feet placed upon a stool is also one of 
the most secure against the approach of the electric fluid. 
An object is said to be insulated when surrounded by 
non-conductors of electricity. 

Why is it unsafe for people in a thunder storm to have metallic 
substances about their persons ? 

What are the most safe positions in a thunder storm ? 



ELECTRIC MACHINE. 79 

Glass being a non-conductor, it is safer to have win- 
dows closed in a thunder storm, than open. 

But after all our care, (and it is proper that we should 
use all the means in our power for our own preserva- 
tion), we must ever reflect that life is in the hands of Him 
who gave it. He can call up storms when we are trav- 
elling in the open sky with no means of escape ; and 
He can even cause the very laws which He has estab- 
lished over nature, to vary whenever it is His will to 
take the life of man in a peculiar way. Thus, at times, 
the most skillful physicians find their usual remedies 
powerless, or producing contrary effects from what they 
have in other cases observed. This shows us that it is 
God and not nature who governs the universe ; since 
nature herself is made to bend to His will. 

Buildings may generally be secured from the effects 
of the electric fluid, by means of what are called light- 
ning rods. These are long rods of iron, being at the 
upper end pointed, while the lower end is placed in the 
earth. The lightning rod should be higher than the 
building; then if there be a discharge of the electric 
fluid from a cloud near the building, the metallic points 
attract it, and the rod conducts it downwards into the 
earth. 

In general the conductors and non-conductors of ca- 
loric correspond to those of electricity. 

THE ELECTRIC MACHINE. 

The electric machine, as represented, in the figure, is 
constructed for the purpose of showing many curious 
experiments which may be made by accumulating the 

Why is it more safe to have windows closed in a thunder storm 
than open 7 

What reflection is here made 1 

How may buildings generally be secured from the effects of 
electricity 1 

Describe an electric machine. 
7 



80 



CHEMISTRY FOR BEGINNERS, 







electric fluid. This machine consists of two principal 
parts, a glass cylinder A, so fixed that it may be turned 
by means of a wheel, and a conductor B, which is either 
composed of some metal or of wood coated over with 
metal ; besides these parts is the rubber R, which is a 
piece of silk hanging loosely over the cylinder and the 
chain C, which falls from the rubber to the ground. 
By turning the cylinder rapidly, the rubber gives off 
electricity and again receives it from the earth by means 
of the chain. The cylinder, being supported by glass 
legs which are non-conductors, does not give off its 
electricity until some conductor is presented ; the me- 
tallic cylinder, being placed in contact with the glass, 
receives the electric fluid as it is accumulated by means 
of the friction with the rubber. 

If a person place his hand upon the knob of the 
prime conductor, opposite the glass cylinder, w T hen it is 



How are electric shocks received from the machine ? 



POSITIVE AND NEGATIVE ELECTRICITY. 81 

thus charged with electricity, he receives a severe shock ; 
if many persons take hold of hands, thus forming a long 
line from the one touching the prime conductor, each 
one would feel the electric shock, and apparently at the 
same instant as it was felt by the person next the con- 
ductor. 

The Electrophorus (or bearer of electricity,) is a very 
simple machine which was invented by an Italian chem- 
ist, Volta, and which may be used for illustrating many 
of the phenomena of electricity. It consists of two plates 
of wood, two or three inches thick ; the lower one is 
covered with a mixture of sealing wax and resin, which 
are non-conductors, but capable of a high degree of elec- 
trical excitement ; the upper plate is covered with tin 
foil, a conductor of electricity, and to this is attached a 
handle of silk which is a non-conductor. 

The lower plate may be excited in various ways ; fur 
being an important agent in accumulating the electric 
fluid, is generally used. After rubbing the resinous 
plate, let the other be placed over it, at the same time 
touching it with the finger, and the metallic, or upper 
plate, will be found charged with electricity. 

POSITIVE AND NEGATIVE ELECTRICITY. 

When a body contains more than the usual quantity of 
the electric fluid, it is said to be in a positive state, when 
less, in a negative state. These two states are some- 
times expressed by the terms plus, more, and minus, less. 

Opposite electricities attract, while similar electrici- 
ties repel each other ; that is, a body in a positive 
state, attracts a body in a negative state ; while two bod- 
j . , . 

Describe the Electrophorus ? 

How is the lower plate excited 1 

When is a body, with regard to electricity, said to be in a posi- 
tive and when in a negative state 1 

What is said with respect to the attraction and repulsion of 
opposite and similar electricities ? 



82 CHEMISTRY FOR BEGINNERS. 

ies, both in a positive, or both in a negative state, repel 
each other. 

A stick of sealing* wax, or a glass tube, rubbed with 
a silk handkerchief, are in a different state of electricity 
from the surrounding bodies, and will attract light sub- 
stances if presented to them. If some little balls of pith, 
suspended by a fine thread of silk, be presented to a 
body which is electrically excited, the balls will at first 
be attracted towards it. If one ball be brought in con- 
tact with the excited substance, and the attempt made to 
suspend it by the side of the other balls, it will be re- 
pelled. 

The cause of this is, that the one ball acquiring from 
the excited electric, a new portion of electricity, commu- 
nicates a portion of it to the ball which it touches, and 
thus they are both excited, and, like two persons under 
the influence of angry feelings, mutually repel each 
other. But if one of the balls in this situation be touched 
with the finger, it will give off its electricity and return 
quietly to its companions. 

The mere contact of different metals, and of many 
other substances, produces opposite electrical states. 

galvanic electricity. — Its Discovery. 

There is a mode in which electrical phenomena may 
be produced, called Galvanism. This is so named from 
Galvani an Italian, who near the close of the last centu- 
ry, discovered that the muscles and nerves of dead ani- 
mals may be excited by the electric fluid ; or, rather, this 
is said to have been the discovery of Madame Galvani, 
who being in her husband's laboratory or place for 
chemical experiments, accidentally observed convulsions 
in a dead frog which chanced to lie near the electrical 
machine, when in action. 

Give some exemples of attraction and repulsion. 

How do you explain these cases of attraction and repulsion 1 

What produces opposite electricities % 

What can you say of the discovery of galvanism 7 



GALVANISM. 83 

On examination by the professor, it appeared that a 
knife, in contact with the machine, had touched one of 
the legs of the frog- ; and that when any other metallic 
substance touched a nerve of the animal, a spark from 
the electric machine always produced a twitching of the 
limb. 

Since then, many discoveries have been made of the 
astonishing effects of galvanic electricity. Some phi- 
losophers have been so enthusiastic as to believe that 
the dead might be restored to life, by its power. Various 
experiments have been made upon the dead bodies of 
criminals ; and although terrible and appalling contor- 
tions of the frame, and frightful changes of countenance 
were produced, still it had not the power to restore life, 
for, as soon as the galvanic action ceased, its effects dis- 
appeared. 

When two metals are connected by some substance 
capable of exciting their different electricities, galvanic 
effects may be observed. For instance, take a piece of 
silver and a piece of zinc, place the silver upon, and the 
zinc under the tongue, and bring their edges together 
at the tip of the tongue; you will instantly perceive a 
singular metallic taste, a slight twitching of the nerves 
of the tongue, and a flash of light. 

Place a piece of silver on one of zinc, and a worm on 
the silver, and it will not be affected ; but if it be brought 
in contact with the zinc and silver at the same time, it 
will writhe as if in distress. 

Acids of various kinds, and water are found useful 
in promoting the developement of electricity in metals ; 
thus the moisture of the tongue in the limbs of the 



What seemed necessary to be brought in contact with the nerve 
of a frog in order to produce a motion in the limbs ? 

What is said of experiments which have since been made, of 
the different applications of galvanism 7 

What case is mentioned in which silver and zinc produce gal- 
vanic effects? 

How may a worm be made to show the effects of galvanism ? 
7* 



84 CHEMISTRY FOR BEGINNERS. 

the skinned frog, and in the substance of the worm, 
were essential in producing the galvanic effects which 
have been described. 



GALVANIC CIRCLES. 

The cut represents a vessel containing an acid, much 
diluted with water, and two plates, the one of zinc, the 
other of copper, as shown by the letters z, and c ; to each 
plate is -soldered a piece of wire, 
which meet in the centre, oppo- 
site the place of insertion. This 
is called a simple galvanic cir- 
cle. It is supposed that when 
in operation, there is in such a 
circle, a continual current of 
electricity, flowing in the direction of the arrows which 
appear in the cut, from the zinc to the fluid, from the 
fluid to the copper, and from the copper, back to the zinc. 
When the wires do not communicate with each other, 
the galvanic circle is said to be broken ; — the wire at- 
tached to the copper plate is negative, and that attached 
to the zinc plate positive ; the wires are also called poles, 
thus we say the copper is the negative pole, and the zinc 
the positive pole. 

A compound galvanic circle consists of many simple 
circles, by means of which a powerful action is produced. 
The Voltaic pile is so named from an Italian chemist, 
Volta. This is made by placing pairs of zinc and cop- 
per plates, one above another. Here we have a se- 
ries of simple circles ; between each pair of plates is 
placed a piece of cloth, wet with a weak acid. The 




What substances are found useful in promoting the develope- 
ment of electricity in metals 1 
What is meant by a simple galvanic circle 1 
What is a compound galvanic circle ? 
How is the the Voltaic pile composed 1 



GALVANIC CIRCLES. 



85 




the electric current. 



figure shews you a Voltaic pile, 
commencing with zinc z, and 
ending with copper c. The 
wires which meet in the centre 
are two poles. The arrows show 
by their points the direction of 




The couronne de 
tasses* is a galvan- 
ic circle in which 
the acid solution is 
contained in separ- 
ate cups. Each 
cup contains a pair 
of plates, and each 
zinc plate is attach- 
ed by a wire, to the 
copper of the next 
pair. These cups, by being multiplied or diminished in 
number, increase or lessen the action of the galvanic 
fluid. 

Dr. Hare of Philadelphia, who has done much for 
the honor of American science, has invented an appar- 
atus called a calorimoter, or mover of caloric. It is 
very powerful in exciting heat, while its power of ex- 
citing electricity is comparatively small. Another and 
more important invention of Dr. Hare is his deftagra- 
tor, or an instrument exceeding all others in its power 
to burn metals, and those substances which resist all 
the ordinary effects of heat. As you advance in your 
knowledge of Chemistry, you will find, in the construc- 
tion and operation of these instruments, much to ad- 
mire. 



* Pronounced couron-de-tas ; meaning crowns of cups. 



Describe the Couronne de Tasses. 

Is heat always accompanied by the same proportions of elec- 



86 CHEMISTRY FOR BEGINNERS. 

It has recently been maintained by chemists, that elec- 
tricity was the great agent in all cases of chemical affin- 
ity, and combination. You will recollect, in consider- 
ing the subject of affinity,- we found that substances 
most unlike, unite the most readily, as in the case of an 
acid and alkali. Now we find these substances to have 
opposite electricities, and that opposite electricities do 
attract one another ; therefore, the inference is in favor 
of electricity, as being the great connecting link in the 
chain of the material creation. 

MAGNETISM. 

There is a form in which electricity appears, called 
magnetism. The power of the magnet to attract and 
repel bodies, appeared mysterious, until discoveries in 
electricity, suggested the idea, that this fluid was the 
agent in the phenomena of magnetism. 

Electricity when accumulated produces certain effects, 
many of which have been already laid before you. But 
the new appearances which magnetism exhibits are sup- 
posed to be owing to the electrical fluid moving in cur- 
rents around the magnet. 

The following are among the most important proper- 
ties of the magnet: — 1. It attracts iron and steel* 2. 

* I have just read an account of the power of the magnet, which 
cannot bat interest the pupil. A young man engaged in some 
mechanical operation, unfortunately had a small sharp bit of 
steel fix itself in his eye ball. The pain which it produced was 
distressing; no relief could be obtained, and it was determined 
that he must submit to the operation of having his eye ball taken 
out in order to save his life. Some person suggested the use of 
the magnet — a powerful one being applied to the eye, the bit of 
steel left it and fastened itself to the magnet. Such are the bene- 
fits of science ! 

What is said of the connexion of electricity with Chemistry ? 
"What has in some measure solved the mystery of the attraction 
of the magnet % 

To what is magnetism attributed 1 

What are some of the most important properties of the magnet? 



MAGNETISM. 87 

When allowed to move freely, it points towards the poles 
of the earth, and each end always points to the same 
pole. 3. The natural magnet has the power of impart- 
ing its properties to other bodies. 4. All magnets have 
a north and south pole. 

You have heard of the magnetic needle or mariner's 
compass. It is by means of it, that the navigator, when 
upon the broad ocean, knows in what direction to steer 
his course; because the north pole, or end of the needle, 
points to the north pole of the earth, and the south pole, 
or end of the needle points to the south pole of the earth. 

Now supposing that there are currents of electricity 
constantly flowing around the globe; that a current 
from one end of the magnetic needle is attracted by a 
current from the north pole of the earth, and another 
from the other end of the magnet is attracted towards 
the south pole ; this would explain the phenomena. 

But we are to imagine that the currents from the 
north pole of the earth and the north pole of the magnet, 
are of opposite electricities, since such only attract each 
other. Thus we find that the north poles of two mag- 
nets repel each other ; while a north pole of one, attracts 
the south pole of another magnet ; from whence we 
learn, that similar poles repel, while contrary poles attract, 
each other. 

The magnet, so called from Magnes, the discoverer, is 
familiarly called the loadstone. It is known in Chemis- 
try as an oxide of iron ; the natural magnet has the 
power of communicating its own properties to iron and 
steel, when brought in contact with them. 

It has been discovered that the conducting wires of 

How is the mariner's compass useful 1 

What reason may be assigned why one end of the magnet al- 
ways points to one pole of the earth, and the other end to the other 
pole £>f the earth 1 

Do similar poles of the magnet attract or repel each other? 

What is the substance called the magnet, and why was it thus 
named 1 



88 CHEMISTRY FOR BEGINNERS 

the galvanic circle communicate to some metals mag- 
netic attraction ; this seems to confirm the theory that 
magnetism is but a modification of the electric fluid. 

If the imponderable agents, light, caloric, electricity, 
and magnetism, are not all essentially the same sub- 
stance, appearing under different modes, they must be 
connected by some common tie, since they so closely 
attend upon and follow the steps of each other. What- 
ever these imponderable substances may be in their 
nature, or whatever bond of union may exist between 
them, we feel that they are mysterious and powerful 
agents operating within our own bodies, around us on 
every side ; constituting the soul of material things, 
and keeping in action the elements of nature — and yet, 
after all, these are passive instruments in His hand who 
created them, and gave them laws. 



CHAPTER IX 



Alphabet of Chemistry. Gases. Mode of collecting 
Gases. Oxygen. 

You will recollect that the great object of Chemistry 
is to ascertain what things are made of, and how they are 
put together — we ought also to add another part of the 
office of Chemistry, which is to show what are the prop- 
erties of bodies ; that is, what changes they are suscepti- 
ble of themselves, and what changes they can produce in 
other bodies. 



What seems to confirm the theory that magnetism is the same 
thing as electricity 1 
What general remark is made, respecting imponderable agents 1 
What are the two important objects of Chemistry ] 



ALPHABET OF CHEMISTRY. 89 

The teacher of Chemistry must proceed with his pu- 
pil, like one who- teaches a child to read. We should 
expect he would first teach the alphabet of letters, out 
of which, words and sentences are made. The pupil in 
Chemistry must learn his alphabet, before proceeding to 
the compounds which are formed with it. 

The alphabet of Chemistry consists of about fifty sim- 
ple substances, called elements. 

The ancients considered that there were but four sim- 
ple elements, viz : fire, air, earth, and water. The three 
atter, are now known to be compounds; while the list 
of simple elements is increased by substances of which 
he ancients knew not even the existence, and by others 
which they considered compounds. 

Among- the substances unknown to the ancients, are 
pases, w T hich do not exist in nature in a separate form, 
but are obtained, by being disunited from their combina- 
tions, by chemical means. Among the simple elements 
supposed by the ancients to be compound, are the metals. 

By the alchemists of former days, a set of men, who, 
with some vague ideas of chemistry, were wholly igno- 
rant of its true principles, it was thought that the less 
valuable metals, such as iron, lead, &c. might be so re- 
duced and purified as to produce gold. 

The alphabet of Chemistry, or the simple substances, 
}f which the science treats, may be arranged as follows : 

1. Imponderable agents. 2. Ponderable substances. 
These consist of 

1. Metals, about 40 

2. Combustibles, (not metallic) 7 

3. Supporters of Combustion, 5 perhaps more. 

How ought the teacher in Chemistry to proceed 1 
What does the alphabet of Chemistry consist of? 
What was the opinion of the ancients in respect to elements? 
What substances were unknown to the ancients, and what sim- 
) le substances did they consider compound ^ 
What is said of the alchymists ? 
How may the alphabet of Chemistry be arranged 1 



90 



CHEMISTRY FOR BEGINNERS. 



By the various combination of these 52 substances, every 
material thing on earth is formed ; as are all the words 
used in our language, formed of the 24 letters of our 
alphabet. 

GASES. 

Among the simple elements is a very important class 
of substances, called gases. The term gas is derived 
from the German, and signifies spirit ; it is applied to 
all aeriform fluids, except the atmosphere, which is called, 
by way of distinction, the air. 

Some gases are lighter, others heavier than the air. 
Some promote combustion, others extinguish it. Some are 
coloured, as red and green ; others are white and invisi- 
ble like the air. Some are destitute of smell, while 
others throw off offensive or suffocating odours. 

MANNER OF COLLECTING GASES. EXPLANATION OF THE PNEUMATIC 
CISTERN. 

Some gases are 
collected through 
water; others which 
have an affinity for 
water, and readily 
mix with it, are col- 
lected through mer- 
cury. Should some 
of the pupils who use 
this book, not have 
— the advantage of see- 
ing chemical exper- 
iments, as they pro- 
ceed in their study, 
they may obtain an idea of the manner in which gases are collect- 
ed, from the figure here presented. A represents a furnace ; B, 
a retort, containing the substance which furnishes the gas ; C, 
Pneumatic cistern; D, receiver; E, F, shelf. Through the 
centre of the cistern, is a narrow piece of board forming a shelf, 
above which the water of the tub rises a few inches. The shelf 




What is meant by a gas 1 
What comparison is made between the gases 1 
Describe the pneumatic cistern, and the method of collecting 
gases over it ^ 



COLLECTING GASES. 91 

has holes through which the necks of gas bottles may be introduc- 
ed ; — sometimes wide mouthed vessels, such as bell glasses are 
used, in which case the vessel can rest upon the shelf, and but part 
of the mouth extend beyond the sides of the shelf. Now suppose 
we wish to collect some kind of gas — if we should introduce it 
into a vessel empty of any thing else, yet filled with the common 
air, (which penetrates every unoccupied space,) the gas would 
mix with the air, and be impure, or its qualities destroyed. For 
this reason the vessels which are to receive the gas are filled 
with water, and placed in an inverted position on the shelf, as 
appears in the figure. If any air, or gas is now introduced into 
the water, under the mouths of the vessels, it will ascend in bub- 
bles. Air may be thus introduced by plunging into the cistern 
a vessel, with its mouth down and just below the mouth of the 
inverted vessel. As the one vessel fills with water, air will be 
pressed out and will rise in bubbles into the other vessel ; as fast 
as air ascends it takes the place of the water which gradually 
lowers until, if there is enough air introduced, the inverted 
vessel is filled with it. In this manner air may be emptied out of 
one vessel into another. Now if any kind of gas is introduced, 
in the same manner it may be collected in the inverted receivers. 
Those of you who can have access to a pneumatic cistern, should 
not fail to exercise yourselves in transferring common air from 
one vessel into another, and indeed of collecting gases where an 
opportunity presents. Any person can put a piece of board over 
a tub, and with water and two tumblers, may learn by practice, 
(the best of all methods,) how to collect gases. 

Two things in this process may seem at first unaccountable to 
you ; the manner in which the water remains in the inverted ves- 
sels, and the displacing of the water by the air W'hichis introduced 
below. The water remains in the vessels, because the pressure of 
the atmosphere on all sides, supports it; and it would support 
an unbroken column of water thirty-two feet high, as in the case 
of pumps where water is brought upwards by first pumping out 
the air ; the vacuum beiug instantly filled with water. The bar- 
ometer which has been described,* is constructed on the same 
principle. The air or gas rises through the water because it is 
lighter ; if oil were introduced below the mouth of the vessel of 
water, it would rise in the same manner, for that is lighter than 
water.t 

* See page 50. 
+ Note to teachers. It is often difficult to explain in words very simple processes. 
The experienced teacher will always supply, by explanations and illustrations, any 
deficiency of the text book. The gas apparatus ma. be exhibited in a small cheap 
way, and it is an important lesson in natural philosophy to observe the suspension 
of a liquid, the ascent of air, and the consequent displacing of the liquid. 

What two things in this process may at first appear unaccoun- 
table 1 



92 CHEMISTRY FOR BEGINNERS. 

OXYGEN GAS. 

The first gas, which we shall consider, is one that 
always exists in nature in combination with other sub- 
stances, and can only be obtained by separating it from 
them. This gas is an important part of air and water. 
It is the great souring principle ; that is, a large propor- 
tion of it combined with a substance produces an acid. 
United to sulphur it forms sulphuric acid, and cider by 
being combined with it becomes vinegar. 

The name of this gas is oxygen. It is so called from 
the Greek oxus, acid, added to gennao, to produce, be- 
cause it produces acids. Other names have been at 
different times given, such as fire air, because it is im- 
portant in combustion, and respirable air, because it is 
a part of the atmosphere necessary to the support of an- 
imal life. 

Oxygen may be obtained in various methods ; that 
which is most common is, by heating a substance called 
the peroxide of manganese ; — this is usually found in 
connexion with iron ore, to which it bears a resemblance. 

An oxide signifies a union of a substance with a small 
proportion of oxygen ; a deutoxide, denotes a greater pro- 
portion of oxygen ; and a peroxide, the highest propor- 
tion of oxygen with which a substance can unite, with- 
out being an acid. 

The peroxide of manganese is a substance composed 
of a metal called manganese, united to oxygen in the pro- 
portion of 100 parts of the former, to 56 parts of the 
latter. On the application of heat, caloric unites with 

What is said of the first gas which we shall consider 1 

What is the name of this gas 1 

How is oxygen obtained 1 

What do you understand by the terms, oxide, deutoxide, and 
peroxide 1 

What is the peroxide of manganese, and what is the effect of 
heat upon it 1 



OXYGEN. 



93 




the oxygen of the metal and carries it off in a gas ; so 
that oxygen gas is in reality composed of a base, oxygen, 
united to caloric. 

The figure shows 
you an egg shaped 
vessel, called a re- 
tort, c, a pneumatic 
tub or cistern, b, 
having a bell glass, 
<&, called a receiver, 
filled with water, 
and inverted over 
it. The retort is 
supposed to contain 
pulverized manganese, it is placed over a lamp, and its 
neck passes under the mouth of the receiver. As soon 
as the retort is heated to redness, oxygen gas begins 
to pass through the tube ; at first it is impure, being 
mixed with the air which was in the retort ; therefore 
the first gas that comes over should be suffered to pass 
into the cistern ; in a short time all the atmospheric 
air being expelled, pure oxygen will appear. The 
neck of the retort being then placed in a suitable po- 
sition, large bubbles of the gas will pass rapidly up and 
displace the water in the receiver. When the gas 
ceases to issue from the retort, the manganese has 
parted with all the oxygen that may be expected. 
What remains in the retort will be a deutoxide of man- 
ganese. 

One pound of the peroxide of manganese, if good, 
will furnish from four to five gallons of oxygen gas. 
Red lead, which is a deutoxide of lead, is often used for 
collecting oxygen gas in the same manner as we have 



Explain the process of obtaining oxygen gas, as represented by 
the figure ? 



94 



CHEMISTRY FOR BEGINNERS. 



just described. Vegetables give off oxygen when acted 
upon by the sun's rays ; though in the dark they exhale 
an unhealthy gas, called carbonic acid gas. 

Having obtained oxygen gas, there are a variety of 
beautiful and interesting experiments which may be 
made with it — these experiments show us the nature 
and properties of this wonderful substance. We say 
substance, because, although we can neither see, smell, 
nor taste it, it is one of the a most powerful and active 
agents in nature. 



The properties of ' Oxygen Gas. 

1. Oxygen is the great supporter of combustion; — that 
is, its presence and aid are necessary to the burning of 
substances. Experiment. — We will 

suppose the glass vessel 
represented in this figure, 
standing upon the shelf in 
the pneumatic cistern, and 
filled with oxygen gas. Its 
purity is tested by introduc- 
ing into the vessel a lighted 
taper ; if it burn with in- 
creased brilliancy, it is pure, 
oxygen gas. A piece of 
fine iron-wire having been 
prepared into a coil, by 
winding- around a larger 
wire, has at the end a piece 
of thread covered with sul- 
phur. Having been infla- 
med by holding it for an in- 




What maV be done with oxygen gas after obtaining it 1 
What is the first property of oxygen which is mentioned 1 
What experiments hows that oxygen is the supporter of com- 
bustion 1 



OXYGEN. 95 

stantinthe flame of a lamp, the coil of wire is theh plun- 
ged into the vessel of oxygen ;— a beautiful and splendid 
appearance is now presented by the burning of the metal, 
which throws ofl sparks glittering like the most brilliant 
stars. If there were sufficient oxygen, the metal would 
continue to burn, until the whole wire was consumed. 
The product of this combustion is a little ball of melted 
iron, which will fall into the water at the bottom of the 
vessel. 

Explanation. — Oxygen, being a powerful supporter of 
combustion, is capable of igniting metals, surrounded by 
it, with some increase of temperature at first. The 
thread, dipped in sulphur and inflamed, gave the first 
impulse to combustion, and the oxygen gas supported, 
and gave it the force and power which this experi- 
ment manifests. In this process, the caloric which ex- 
isted in combination with oxygen gas, is pressed out by 
the union of oxygen with the iron wire. The little ball 
of iron is an oxide of iron, and on being weighed, is 
found to be heavier than the wire before it was burn- 
ed ; this shows that it has gained something ; and since 
there was only iron and oxygen gas, in the vessel, 
besides the caloric necessary to hold oxygen in the state 
of a gas, and this has been seen to come out from its 
latent to a free state ; we must, since the oxygen has dis- 
appeared, conclude that it united with the iron, which 
conclusion is confirmed by the fact, that the iron has ac- 
tually acquired something which adds to its weight. 

We see from this experiment, that if the air were pure 
oxygen, every thing would be consumed. No sooner 
would a fire be kindled in an iron stove, than the stove 
itself would begin to burn. The brass tube of the bel- 
lows with which we blow the fire, would itself burst into 



How do you explain the appearances exhibited in this experi- 
ment 1 
What consequences would ensue if the air were pure oxygen 7 
8* 



96 CHEMISTRY FOR BEGINNERS. 

an intense blaze, and the blacksmith, in attempting to 
pursue his labours, would see his hammer and anvil kin- 
dling into a flame. 

But the Author of nature has in this, as in all his 
works wisely and kindly ordered his works, so that 
the life and comfort of his creatures are preserved 
and promoted. He has therefore given to the air that 
proportion of oxygen which promotes the combustion of 
wood, oil and coal sufficiently for all the purposes of 
human life ; less oxygen would be insufficient to afford 
us the necessary fire and light; more oxgyen would 
render combustion dangerous and destructive. 

The oxygen of the air is diluted or tempered with 
another gas, called nitrogen, which" we shall soon ex- 
amine. 

It is important that you should consider attentively 
what takes place in burning or combustion. You have, 
in the burning of metal, understood that though there is 
a change of state in the two substances, oxygen gas and 
iron, yet neither of them are destroyed or lost. This is 
the case with every thing that burns ; nothing is de- 
stroyed, but substances in burning change their state or 
condition. Some portion passes off in smoke or vapour, 
another remains in the form of coal, ashes or soot. 

Philosophers say, and the assertion appears to be prov- 
ed by all the experiments which have yet been made upon 
material substances, that no portion of matter has ever 
been destroyed. Thus we find that not even in burning, 
which seems the most destructive of all processes, is any 
particle lost, who then would dare to say, since God thus 
saves every material atom that he has created, that he will 
annihilate the noblest of his works, the human soul % 

What is remarked of the adaptation of things by the Creator 
for the good of his creatures 1 

By what is the oxygen of the air dijuted 1 

Are substances destroyed by burning 7 

What argument for the immortality of the soul, seems to be af- 
forded by the fact here stated 1 



OXYGEN. 97 

Combustion, or Oxidation. 

The union of any substance with oxygen is consid- 
ered as a kind of combustion or burning. Iron rust is 
an instance of slow combustion ; this is an oxide of iron. 
Any iron vessel or utensil which stands long exposed to 
the weather will become rusted. Iron has such an affin- 
ity for oxygen, that it attracts it from the air, and from 
the moisture which is in the air ; if the vessel is left with 
a little water in it, the oxygen from the water hastens the 
process of oxidation. 

You will recollect that a burnt and an oxidated 
substance mean the same thing. All bodies which 
will unite with oxygen are therefore called combustible ; 
the metals, gases, and indeed all the simple elements, 
unite with oxygen in a greater or less degree. 

There are various degrees of oxidation, the lowest is 
called an oxide, the highest an acid. Some substances 
unite with oxygen in only one proportion, others in 
four. The lowest proportion in which oxygen unites 
with any substance is 8 ; therefore this is considered 
the representative number of oxygen ; a second propor- 
tion of oxygen would be 16, a third 24, and so on, each 
being some multiple of 8. 

Oxygen important to Animal Life. 

2. A second important property of oxygen is, it supports 
respiration, or breathing. 

A little girl caught a beautiful humming bird, and 
to secure it till she could procure a cage, put it under 
a large bowl. In a little time, going to look at her 
bird, she found to her sorrow that it was dead. Had 

What is iron-rust an instance of, and why is it that this sub- 
stance forms so readily upon iron? 

What substances are called combustible 1 

What is said of different degrees of oxidation 1 

What is the second important property of oxygen, and what 
anecdote is related in order to illustrate this 1 



98 CHEMISTRY FOR BEGINNERS. 

she understood Chemistry, she would have known that 
the bird, small as it was, would soon consume in 
breathing all the oxygen contained in a bowl full of air, 
and then nothing would be left but nitrogen, which can- 
not support life, and another gas thrown off in breathing, 
viz. carbonic acid, which is destructive to life. 

If you put a lighted taper or candle into a glass 
vessel of common air, it will at first burn as 
usual, but soon grow dim, and at length be wholly ex- 
tinguished. This is because all the oxygen of the air 
is consumed. Thus, in a tight, crowded room, 
we perceive the lights to become dim, and 
persons often faint, requiring to be carried 
where they can have fresh air. Both the 
burning of the lights and the breathing of the 
people, exhaust the air of oxygen, and al- 
though there is no ordinary room but admits 
some air, still, under such circumstances, 
the main body of the air must be unwholesome. No 
animal can live in air that will not support combus- 
tion. But beside the want of oxygen, there are other 
circumstances which render the air in certain situa- 
tions destructive to life and combustion. We shall 
consider this more particularly when we treat of car- 
bonic acid gas. 

Oxygen the great Acidifying principle, 

3. A third important property of oxygen is, that it pro- 
duces acids. It was long considered as the only maker 
of acids which exists, and is now supposed to be of much 
greater importance in this respect than any other sub- 
stance. 




What may we infer respecting the quality of air, when a candle 
will not burn freely in it. and why does the air in a crowded room 
and with many lights, become bad ? 

What is a third important property of oxygen 1 



OXYGEN. 



99 




The figure represents the burning of a 
substance called phosphorus in oxygen 
gas. The phosphorus is contained in the 
bent spoon, which is introduced into the 
jar of oxygen gas ; on inflaming the phos- 
phorus, it burns with great brilliancy. A 
white, flaky substance which soon ap- 
pears on the sides of the vessel, is then 
rinsed off into water. On tasting the 
liquid it is found to be sour ; it will also 
redden blue vegetable colours, which is 
another proof of its acid property. 

Explanation. — The jar contained only water, oxygen 
gas and phosphorus; nothing now remains of these 
three substances but the sour liquid, therefore we infer 
that the union of oxygen with the phosphorus has made 
it acid; this is called phosphoric acid. 

Cider becomes vinegar, in consequence of uniting with 
a portion of the oxygen of the air. It is, therefore, nec- 
essary, to leave the barrel which contains the cider un- 
stopped, and exposed to the air. Light has also an 
influence in promoting the union of oxygen with other 
substances. The barrel should be but partly filled, in 
order that a greater portion of the liquid may have ac- 
cess to the air at once. 



Discovery of Oxygen. 

This gas was discovered about the year 1774, by Dr. 
Priestly, an English Chemist, though two Chemists, 
Scheele of Sweeden, and Lavoisier of France, are sup- 



What does the figure represent % 
How do you explain this experiment 1 
What is the cause of cider becoming vinegar \ 
When and by whom was oxygen discovered l 



100 CHEMISTRY FOR BEGINNERS, 

posed to have made a similar discovery about the same 
time. Dr. Priestly observed, that by heating certain met- 
als, a kind of air was obtained, much purer than the atmos- 
phere, and in which combustible substances burnt with 
great brilliancy ; such was the simple manner in which 
this wonderful gas was first introduced to the notice of 
the world. Since that period, the whole science of 
Chemistry has changed its character, and all has seemed 
to become subservient to this great agent. ' Oxygen, 1 
says a celebrated chemist, ' may be considered as the 
central point around which Chemistry revolves.' We 
should not fail to inform you that oxygen gas is thrown 
off by vegetables, in a proportion, about as great, as that 
consumed by animals ; thus the one part of creation is 
made to depend on the other. 



CHAPTER X. 



Nitrogen. Atmosphere. Nitric Acid. Law of Defi- 
nite proportions. Nitrous Acid. Nitric Oxide. 
Nitrous Oxide. 

We are now to examine a substance which, though 
resembling oxygen in being a gas, without either colour 
or odour, is yet very different in its essential properties. 

Nitrogen is so called because it exists in nitre ; it was 
at first called azote from the Greek a, to deprive of, and 
zoe, life, because an animal soon dies when surrounded 
by this gas. The French still retain the name azote. 

What is said of the substance now to be considered 1 
From whence are the terms nitrogen and azote derived % 



NITROGEN, 



101 



Nitrogen composes four fifths of the' common air; 
that is, air consists of four parts of nitrogen to one of 
oxygen, when reckoned according to the space they oc- 
cupy ; thus four tumblers of the one with one tum- 
bler of the other, would make a compound, resembling 
the atmospheric air. In estimating by weight, the pro- 
portions are different, for nitrogen is a little lighter than 
the air, and oxygen a little heavier ; thus two propor- 
tions of nitrogen to one of oxygen, when reckoned in 
weight, make common air. The proportional number of 
nitrogen is 14 ; two proportions are 28 ; — the proportion 
of oxygen is 8, therefore these two gases in the atmos- 
phere are as 28 united to 8. 

Nitrogen gas may be obtained in a very simple man- 
ner. Place a bell glass over a vessel containing a little 
f water, and introduce a lighted taper 

jr~^\ under it, as you see in the figure. 
A When the taper goes out, you have an 
evidence that the oxygen of the air has 
been consumed ; the nitrogen which 
does not unite to the burning body is 
left free. As oxygen is absorbed, water 
rises in the bell glass to fill its place. 
By this method of obtaining nitrogen, 
the gas is not left entirely pure, since 
some vapours from the burning taper have mingled with 
it ; but it is sufficiently pure to exhibit the most striking 
properties of this substance. 

Nitrogen destroys Combustion. 

A. very elegant and striking experiment may be made, 
to prove that nitrogen destroys combustion, that oxygen 
supports it, and that a mixture of these two gases in the 
proportion of four parts of nitrogen to one of oxygen, 
makes a compound resembling atmospheric air. 




What is air composed of 1 

How may nitrogen gas be obtained 1 

What may be proved by an experiment ? 



102 



CHEMISTRY FOR BEGINNERS. 




* r f n vi 1 1 1 1 r i nrm nm 1 1 1 1 n n » 1 1 1 1 1 n ty 1 1 »'"'«»' ' i * j ' ' i [H n » » »> I '.' ' '.'jTl 1 ! 1 .! i?»i^- - - 

innmn'iwiiiwi 




Experiment. — Four 
large vials are- repre- 
sented in the cut, 
which you are to sup- 
pose filled as follows; 
the first n, with nitro- 
gen, the second o, with 
oxygen, the third aa, 
with a mixture of the 
two, forming artificial 
air, and the fourth ca, 
with common air, or as we say (though not scientifically) 
empty. A little wax taper suspended by a wire, and 
burning brightly, is first let down into the vial of nitro- 
gen ; here it will be immediately extinguished, but while 
the wick yet remains at a red heat, the taper is plunged 
into the second vial containing oxygen, here it is re- 
lighted and burns 'brilliantly ; the taper is then let down 
into the third vial containing the artificial air, where it 
burns less vividly than in the oxygen, and in the fourth, 
which is filled with common air, it burns exactly in 
the same manner as in the third. 

Explanation. — Nitrogen affording no aid to the burn- 
ing process, the flame of the taper expired — oxygen by 
its energy rekindled it ; and the burning of the taper 
in the two last vials proved that the mixture of nitro- 
gen and oxygen, in the proportions of four to one, formed 
air resembling that of the atmosphere. 

Although nitrogen does not support combustion, it 
does not act as a positive agent, but destroys the flame 
by preventing the approach of oxygen ; in the same 
manner a burning taper, wholly immersed in oil would 
be extinguished. 

Nitrogen destroys animal life ; but as in the case of 



' What does figure the represent 1 
Explain the experiment. 
Does nitrogen by its own power destroy flame 1 



ATMOSPHERE. 103 

combustion, it is not an active agent ; an animal con- 
fined in it, dies for want of oxygen. 

It possesses the positive electricity, as when subjected 
to the action of the Galvanic circle it is attracted to the 
negative pole. 

It is contained in all animal substances, but in few 
vegetables : the cruciform plants, such as cabbage, tur- 
nip, &c. contain some nitrogen. 

Except when combined with other substances, nitro- 
gen is not active in its properties, but it forms many im- 
portant compounds. 

It was discovered about the same time as oxygen ; that 
is about the year 1774, or two years before the Declara- 
tion of American Independence. 

ATMOSPHERE. 

We have examined separately two elements or two 
letters of the alphabet of Chemistry: we have found that 
these combined, form the atmosphere or air. 

This surrounds the globe to an extent not exactly 
known, but supposed to be about forty-five miles in 
height. 

The air was long considered as a simple body, but 
some chemists had begun to suspect its compound nature, 
when Lavoisier proved by a course of experiments that 
it was composed of two gases which possessed very 
different properties ; his discoveries were of great use 
to succeeding chemists in enabling them to ascertain the 
nature of these gases, and tj^e proportions in which they 
naturally exist. 

How does nitrogen affect animals 1 
How is nitrogen affected by the galvanic circle 1 
Is nitrogen contained in animals and vegetables 1 
Is nitrogen important when uncombined with other substances ? 
When was it discovered % 
Of how many elements is the air composed *? 
What is the height of the air 1 

What is said of Lavoisier's experiments upon the air ? 
' 9 



104 CHEMISTRY FOR BEGINNERS. 

Air is now known to consist of 21 parts of oxygen 
gas, and 79 of nitrogen in 100 parts ; it also contains 
aqueous vapour and a small portion of carbonic acid, 
probably one part in a thousand. Though other gases 
may arise from the earth and mingle with the air, neither 
they nor carbonic acid are considered as essential parts 
of it. 

Carbonic acid gas is diffused into the atmosphere in 
various ways, chiefly by the burning of vegetable sub- 
stances and the breathing of animals. The air w T oulcl 
by these means soon become impure, were it not that 
vegetables, needing carbon to promote their growth, take 
it up from oxygen with which it is combined in carbonic 
acid gas, and which being thus disengaged, returns back 
to purify the air. In countries where a low temperature 
during a part of the year, as in New England, prevents 
the active growth of vegetation, the winds which agitate 
the atmosphere, and the mosses and evergreen maintain 
an equilibrium in the proportion of oxygen in the atmos- 
phere. 

Atmospheric air has neither colour nor smell ; in these 
respects it resembles oxygen and nitrogen gas ; its 
weight or specific gravity is estimated as 1, the weight 
of all other aeriform fluids being settled by a comparison 
with it ; thus the specific gravity of oxygen is 1.1 1, or a 
fraction more than the -weight of air, while that of nitro- 
gen is .9722, or less than a unit. * 

It is not entirely settled among chemists, whether the 
air is merely a mixture of the two gases, or a chemical 
combination. If it were only a mixture, we should ex- 
pect the heaviest portion, oxygen, would settle below 
the other part; but we do. not find in portions of air 

What is air now known to consist of, and what substances min- 
gle with it, that are not considered as essential ingredients'] 

What prevents carbonic acid from increasing so much as to 
destroy the purity of the air 1 

What is said of the colour, smell, and weight of the air ? 

Is air a mdzi/tire. or a chemical combination? 



NITRIC ACID. 105 

standing in a vessel undisturbed, that this separation 
does take place — and yet the experiment of making ar- 
tificial air, by simply mixing the two gases, would tend 
to prove that it is not a chemical combination, or if so, 
that the affinity is not strong between the gases, since 
the union takes place without any agitation. 

The following are some of the most important proper- 
ties of air: it is a bad conductor of electricity and 
heat; it supports combustion ; by parting with oxygen 
it causes acidity in many liquids; it oxidizes metals ; 
it is necessary to breathing, on account of the oxygen 
which it contains ; it is heaviest near the earth ; it is 
coldest in the higher regions ; it may be compressed by 
being subjected to a heavy weight ; and it may be di- 
lated by heat. 

When air is decomposed, it is always the oxygen 
which unites with other bodies ; no substance is known 
which will absorb nitrogen from the air. 

We shall now observe some other combinations of the 
two gases which form the atmosphere ; but instead of 
a mild substance like the pure air, we shall here find one 
of the most destructive and corroding of all the acids. 

NITRIC ACID. 

Nitric acid is so called because it was first obtained 
from the nitrate of potash- (saltpetre) ; it was at first 
called the acid water of nitre, afterwards spirits of nitre, 
and aqua fortis ;* it was called nitric acid in 1782 by 
the French chemists. 

* Aqua fortis means strong water, being from the Latin aqua., 
water, and fortis, strong ; this is the common name for nitric acid' 

Mention some of the most important properties of air. 

In order to decompose air, which of its elements unites with 
other substances ? 

Are all the combinations of o^jgen and nitrogen mild like the 
air'^ 

Why is nitric acid thus named ? 



106 



CHEMISTRY FOR BEGINNERS. 




Experiment. — This acid may be obtained by the fol- 
lowing method ; three parts of pounded saltpetre, or ni- 
trite of 'potash, 
are put into a 
tubulated retort, 
such as you see 
in the figure at 
a; upon this is 
poured sufficient 
sulphuric acid to 
wet it; on apply- 
ing heat to the 
retort from the 
lamp at d, the ni- 
tric acid gas will 
begin to pass o- 
from whence it will pass into 
the bottle c, where it will be absorbed by water, a small 
portion of which had been put into the bottle for that 
purpose. Upon examining the water it will be found to 
be weak nitric acid, or aqua fortis. 

Explanation. — The nitrate of potash is composed of 
nitric acid and potash ; the latter having a stronger affin- 
ity for sulphuric than for nitric acid, unites with it, and 
the nitric acid being excluded, passes off in gas. The 
use of the tubulated retort is to let out the common air 
w r hen the gas begins to ascend, and also by the little tube, 
the sulphuric acid is introduced after the apparatus is 
fitted in the manner represented by the cut. A glass 
stopper closes the aperture when necessary ; at e e is rep- 
resented a lamp-furnace and a stand, which are very im- 
portant parts of a chemical apparatus. 

Nitric acid, when combined with water, is called hy- 
dro-nitric acid, from the Greek udor, water, w T hen in a 



ver into the receiver b 



What experiment is figure the designed to illustrate 1 
Explain this process. 

What are the different names for nitric acid when with or 
without water ? 



LAW OF DEFINITE PROPORTIONS. 107 

dry state, or without water, it is called anhydrous nitric 
acid, from a Greek preposition, signifying without, added 
to the word denoting water; but such is the affinity of 
this acid for water, that it is seldom found entirely free 
from it. 

Its specific gravity, or weight compared with water, 
is 1.5, that is, one and five tenths, which is equal to one 
and a half. 

Nitric acid resembles water in having neither colour 
nor smell, but it is extremely caustic and corrosive ; it 
acts strongly upon animal and vegetable substances. A 
drop of it upon the flesh causes a burning sensation, and 
produces an ulcer as if fire had touched the spot. It is 
actually a burn, since the effects are produced by the ox- 
ygen, which, leaving the acid, unites to the flesh, or ox- 
idates it ; and oxidation, you have learned, means the 
same thing as burning, although there are very low de- 
grees of it, which do not produce the effects commonly 
ascribed to burning. 

It is because nitric acid readily parts with oxygen, that 
it produces the effects we have just described. Most 
combustible substances decompose nitric acid by attract- 
ing its oxygen ; the quantity of oxygen absorbed, varies 
according to the affinity of substances for this gas. 

ILLUSTRATION OF THE LAW OF DEFINITE PROPORTIONS, 
OR ATOMS. 

No part of the study of Chemistry illustrates more 
fully, the law of definite proportions, than that of nitro- 
gen, considered in reference to its various combinations 
with oxygen. This law we have already mentioned in 
several instances. In treating of affinity, we found that 
sulphuric acid united with soda to form the sulphate of 

What is the specific gravity of this acid % 
What are some of the properties of nitric acid'? 
Does nitric acid part with oxygen readily % 
What law is illustrated by the combinations of nitrogen and 
oxygen 1 

9* 



108 CHEMISTRY FOR BEGINNERS. 

soda j but when the two substances had combined ex- 
actly in the proportion to form that salt, their union 
would proceed no farther. 

Nitrogen and oxygen unite in several proportions. 
You may understand this the better if we use the term 
atoms, which some chemists adopt. For instance, 14 
being the lowest proportion, in weight, in which nitrogen 
unites with any substance, this is considered as its ulti- 
mate atom, or the lowest division of it which can be 
made. The lowest proportion in which oxygen unites 
with any substance, is 8, therefore, these are considered 
as the weight of their respective atoms. That of an- 
other gas, hydrogen, one atom of which with 8 of oxygen 
form water, is represented by 1. These atoms may be 
represented by signs thus : 
weight. 

1 — O atom of Hydrogen, 
14 — at " Nitrogen, 

8—0 " Oxygen. 

Water, which is compounded of an atom of oxygen 
and one of hydrogen, may be either represented by the 
sum of 1 and 8, which is 9, or by the signs, O hyd. O 
ox. Air, which is composed of one atom of oxygen and 
two of nitrogen, may be either represented by the sum 
of 8 and 28 which is 36, or by the signs, ox. &*> nit. 

Besides the union of nitrogen with oxygen, forming 
atmospheric air, these two gases unite to form five dif- 
ferent compounds ; viz.: 

Nitrous oxide, one atom Nitrogen 14 to one oxygen 8 
Nitric oxide " <*> = 14 00 = 16 

Hypo*-nitrous acid " cd = 14 OOO = 24 

Nitrous acid " <*> = 14 O O 00 = 32 

Nitric acid " a> = 14 OOOOO = 40 

* Hypo is a Greek preposition signifying under; the term hypo-nitrous acid 
denotes that it is less acid than nitrous acid. 

What numbers express the ultimate atoms of nitrogen, oxygen, 
and hydrogen, and by what signs are they represented ^ 

How may water and air be represented 1 

What otner compounds besides air are formed by the union of 
nitrogen with oxygen 1 



NITROUS ACID. 109 

All these combinations will be seen to be formed either 
with the atom 8, or some multiple of it, as twice, three 
times, four times, and five times 8. The number which 
represents the compound is the sum of all the atoms ; 
thus the representative number of nitric acid is 54, it be- 
ing composed of oxygen 40 and nitrogen 14. 

NITROUS ACID. 

» 

Nitrous acid has been long known in Chemistry ; in- 
deed the chemists of the last century called all the gases 
formed by a union of nitrogen and oxygen, by the gene- 
ral name of nitrous acid gas. But as we have already 
observed, there are now known to be several distinct 
gaseous compounds of this family. 

We have found that nitric acid exists in a liquid state. 
When this substance loses one portion of its oxygen, it 
exhibits red fumes or vapours, and is changed to nitrous 
acid gas. Nitrous acid may also be obtained by heating 
in a small retort, the nitrate of lead. It is remarkable 
for its colour, which at a low temperature is a bright 
orange. When water absorbs this gas, it first appears 
green, then blue, and at length orange colour. The 
liquid when tested, is found to be acid. 

HYPO-NITROUS ACID. 

Hypo-nitrous acid, which means a substance containing 
less oxygen than nitrous acid, though named and de- 
scribed by chemists, seems to be but little understood by 
them ; indeed, they seem to be scarcely certain that they 
have ever obtained it. Since this is the fact, we will not 
puzzle the beginner with attempting to explain at what 
exact point, when uniting with more oxygen to form 
nitrous acid, the nitrous acid passes into the hypo-nitrous 
state. 

Why is the representative number of nitric acid 54 1 
Has nitrous acid been long known 1 
How may nitrous acid be obtained 1 
For what is this gas remarkable? 
What is said of hypo-nitrous acid 1 



110 



CHEMISTRY FOR BEGINNERS. 



NITRIC OXIDE. 

Nitric oxide is also called nitrous gas, and the oleut- 
oxide of nitrogen. It is lower as respects the propor- 
tion of oxygen it contains, than the hypo-nitrous acid, 
and higher than the nitrous oxide, which being the low- 
est combination of oxygen with nitrogen, is called a 
protoxide. 

Nitric oxide may be obtained from nitric acid, by the 
following process. 

Experiment. — Put some small bits of copper, or 
copper filings into a retort, as seen in the figure, and 
pour upon them some nitric acid. As soon as the 

heat of the lamp passes 
into the retort, a violent 
action commences, and 
a red looking gas be- 
gins to pass over; this is 
nitrous acid, which hav- 
ing a great affinity for 
water, unites with that 
in the tub; then appears 
a colourless gas, which 
does not unite with the 
water, but passes through it into the bell glass in little 
bubbles, the water in the bell glass gradually sinks as it 
fills with nitric oxide gas. 

Explanation. — Nitric acid contains five atoms or pro- 
portions of oxygen ; three of these unite with the cop- 
per, and form an oxide of copper ; two atoms of oxygen 
then being left with the nitrogen, form the gas called 
nitric oxide, which passes off through the tube of the re- 
tort into the receiver. 




By what different names is nitric oxide known 2 
Describe the manner of obtaining nitric oxide or the deutoxide 
of nitrogen. 
How is the experiment for obtaining nitric oxide explained? 



NITRIC OXIDE. 



Ill 



But in the retort was a portion of atmospheric air, 
which furnishing oxygen, changed the nitric oxide into 
the red or orange coloured gas, called nitrous acid, 
which united with the water of the receiver. As soon 
as all this was taken up, the pure nitric oxide passed 
over. 

Nitric oxide is of use among chemists to determine 
the proportion of oxygen in the air ; for so great is its 
affinity for this gas that when mingled with common 
air, it attracts all the oxygen, and becomes the red nitrous 
acid, leaving nitrogen free. The nitrous acid which is 
formed, may be wholly absorbed by water. 

In this figure you are 
presented with a very in- 
genious instrument, con- 
trived by Dr. Hare for 
the analysis of atmospher- 
ic air, by means of ni- 
tric oxide. It is called 
a volumescope ., It consists 
of a hollow glass cylinder, 
thirty inches high, and four 
and a half in diameter ; it 
is placed over the pneu- 
matic cistern. On each 
side of the cylinder, there 
are strips of wood on which 
are marked degrees. You 
perceive three tubes ; these 
are of lead, and made flex- 
ible, so that they can be 
bent as may be necessary ; 
the entrance to each of 
these tubes may be closed by the turning of the stop- 
cocks which appear near the places of their connexion 




What useful application do chemists make of nitric oxide 1 
Explain the use of the volumescope. 



112 CHEMISTRY FOR BEGINNERS. 

with the instrument. To one of these tubes is connect- 
ed a pear-shaped bottle which Dr. Hare calls a volume- 
ter (a measurer of volumes, or of equal quantities.) 
This bottle holds just as much air or gas as three de- 
grees of the glass cylindei. Now supposing part of the 
air to be exhausted from the cylinder by means of an air 
pump, to which one of the tubes is made to communi- 
cate ; the water then rises up to fill the vacuum. The 
volumeter being filled with nitric oxide, and a communi- 
cation opened by turning the stop-cocks, gas ascends into 
the cylinder. The orange red fumes of nitrous acid then 
appear. By means of an India rubber bag and tube, jets 
of water are thrown up into this gas, which is soon 
wholly absorbed by the water. The number of degrees 
which the water rises, shows the quantity of gas which 
has been taken up from the air, and as oxygen only 
unites with the nitric oxide, forming, by its union, the 
orange, fuming gas, called nitrous acid, the quantity of 
oxygen which the air contained, is thereby ascertained. 
That is, the whole portion of air having at first been 
measured, by observing how much nitrogen remains, 
we are able to tell the quantity of oxygen which has 
been absorbed.* 

NITROUS OXIDE. 

You know that the termination in ous denotes a lower 
proportion of oxygen than that in ic. Nitrous oxide, 
therefore, as the name would denote, has less oxygen in 
combination with it than nitric oxide, which we have 
just examined. Nitrous oxide is sometimes called the 
protoxide of nitrogen, while nitric oxide is the deutoxide. 

* This somewhat complicated instrument may not be under- 
stood by the young pupil; though its object may be clearly com- 
prehended. As Dr. Hare had kindly forwarded to the author 
some papers containing his recent discoveries and improvements, 
she was anxious to show to the beginner, some of the curious ap- 
paratus by which he so happily illustrates some of the most diffi- 
cult subjects in Chemistry. 

What does the name nitrous oxide denote? 



NITROUS OXIDE. 113 

Nitrous oxide may be obtained from nitric oxide, by 
the action of substances which will abstract one atom of 
its oxygen. 

Nitrous oxide is more like the common air than any 
of the other combinations of nitrogen with oxygen, since 
it may be breathed with more safety. It was quite fash- 
ionable, a few years ago for those who attended chemical 
lectures, to prove the nature of this gas by inhaling it 
into the lungs. It was at first thought to be harmless ; 
but at length cases occurred in which it produced faint- 
ness and distress, and threatened serious injury. The 
effects of breathing nitrous oxide were in many cases 
singular, and often highly ludicrous. It was per- 
fectly intoxicating to many. The most serious persons, 
under its influence would become gay, and vent their 
feelings by immoderate laughter, capering about the 
room, or opening their mouths without being able to 
close them, although sensible of making a most ridicu- 
lous appearance. Fun-loving urchins, and frolicsome 
youths, after breathing nitrous oxide, would sometimes 
suddenly assume the most laughable and incongruous 
gravity of countenance and demeanour, gazing around 
without the power to smile at their own appearance. 
Sir Humphrey Davy, the first who attempted inhaling 
it, breathed four quarts of the gas. Some who repeated 
the experiment after him, declared it must be ' the very 
atmosphere of heaven.' 

It is now acknowledged by chemists, that there must 
danger in inhaling nitrous oxide, from the difficulty of 
obtaining it entirely free from some portion of nitric ox- 
ide, which is suffocating and destructive of life. 

We perceive, in* learning the nature of nitrogen and 
oxygen, that the proportions which the Almighty has 

How may it be obtained 1 
What is said of breathing nitrous oxide % 
What renders it dangerous to inhale nitrous oxide 1 
What fact do we perceive respecting the composition of the air, 
by learning the properties o£ oxygen and nitrogen 1 



114 CHEMISTRY FOR BEGINNERS. 

established between these two gases in the atmosphere, 
are exactly such as the living beings who exist in it need. 
Less oxygen would not be sufficient to support respira- 
tion, more would quicken and stimulate the vital powers 
to a degree which would soon destroy them ; or, as has 
been said, 4 as a candle burns brighter in oxygen gas and 
is more quickly consumed, so in this gas, the flame of 
life would be more vivid, but sooner burnt out.' 

We have now seen that with two elements or letters 
of the alphabet of Chemistry, several substances are 
formed, viz: air, nitrous oxide, nitric oxide, nitrous 
acid, and nitric acid. 

Nitric acid forms with various substances, nitrates, 
and nitrous acid forms nitrites. There are many other 
important compounds formed with nitrogen, which we 
shall notice hereafter, when we have learned something 
about the other elements with which it unites. 



CHAPTER XI. 



Hydrogen. Its properties. Its agency in producing 
Earthquakes and Volcanoes. Water. The Com- 
pound Bloivpipe. 

We are now to examine a new element/ hydrogen ; 
the name of which is derived from the Greek udor, wa- 
ter, added to a word signifying to produce, because that 
in connexion with oxygen it forms water. 



What substances have we found to be formed by two letters of 
the alphabet of Chemistry % 

What are nitrates and nitrites 1 
What doe.s the word hydrogen signify 1 



MODE OF OBTAINING HYDROGEN GAS. 115 

Tn studying the gases we are continually met by new 
and interesting facts ; and the gas, now under considera- 
tion, furnishes its full proportion of beautiful experiments ; 
— but we will first observe the manner in which it is ob- 
tained j this, like oxygen, must always be in a gaseous 
state, since such is the affinity of hydrogen for caloric, 
that it can never be solidified. 

Mode of obtaining Hydrogen Gas. 

Water being composed of hydrogen and oxygen, if 
the oxygen unites to a metal, the hydrogen will be liber- 
ated and pass off in the state of gas. 

Experiment. — Some iron fil- 
ings being put into a flask, and 
weak sulphuric acid poured 
upon them, a lively effervesence 
takes place; the hydrogen gas 
immediately begins to escape, 
| and, by means of the tube which 
passes under the mouth of the 
bell glass, is collected through 
water. Nearly half the water, with which the bell 
glass was filled, has disappeared, the gas having risen 
and taken its place. 

Explanation. — The oxygen of the water being strong- 
ly attracted by iron, leaves the hydrogen and unites with 
the metal ; the hydrogen, which existed in a liquid state 
with oxygen, is no sooner disengaged, than it combines 
with sufficient caloric to become a gas. The manner 
in which sulphuric acid aids the process, is not satisfacto- 
rily explained by chemists. Professor Silliman says, 
' it appears to me better to say that we do not understand 

In what form is hydrogen always obtained 1 
How can hydrogen be obtained from water 1 
What does this figure represent 1 

What explanation may be given of the changes which take 
place in this experiment 1 

10 




116 



CHEMISTRY FOR BEGINNERS. 



it, and to wait till we do, before we attempt to explain 
the fact. 1 The oxygen of the "water uniting to the iron 
filings forms an oxide of iron ; — the sulphuric acid is not 
decomposed, but unites with the newly formed oxide and 
forms a sulphate of iron, (copperas,) which when allowed 
to stand for a sufficient time, appears under the form of 
green crystals. No heat is applied in performing this 
experiment, but so much caloric is disengaged by the 
chemical combination of the sulphuric acid and water, 
as to heat the flask. 

Iron heated to redness, decomposes the steam from 
boiling water, by uniting with the oxygen and setting 
the hydrogen free. 

Properties of Hydrogen. 

Having collected Hydrogen gas, we will proceed to an 
examination of its properties. 1. It is the lightest of all 
substances which have been weighed, that is, of all pon- 
derable substances, being about 14 times lighter than at- 
mospheric air, and 16 times lighter than oxygen. 

Experiment. — The lev- 
ity of hydrogen gas is 
very prettily exhibited by 
the following experiment. 
A bladder fitted for the 
purpose, and filled from a 
bottle of the gas in the 
manner here represented, 
is used to for the purpose 
of blowing bubbles in soap 
suds; these bubbles be- 
ing shaken off the end 




How does hot iron decompose steam 1 

What is the first property of hydrogen which is mentioned 1 

By what experiment is the lightness of hydrogen illustrated 7 



PROPERTIES OF HYDROGEN. 



117 




of the tobacco pipe, which is 
fitted to the mouth of the 
bladder, rise through the air, 
until stopped by the upper 
ceiling of the room. 

Explanation. — The bub- 
bles, being inflated with hy- 
drogen gas, ascend because 
they are lighter than air. 
The figure shows a bubble 
just passing off from the pipe ; 
if a lighted candle is held so 
that the flame comes in con- 
tact with the bubbles, they ex- 
plode and burn. 

Balloons ascend on the 
same principle as these bub- 
bles ; — they are made of oiled 
silk, inflated with hydrogen 
As a large quantity of the gas 
is needed for this purpose, barrels or 
other capacious vessels are used for 
containing the water which is to be 
decomposed, and the hydrogen is 
conducted into the balloon by means 
of long flexible tubes. The ceronaut, 
(as the navigator of a balloon is cal- 
led,) must experience new and sub- 
lime emotions as the car in which 
he sits, rises aloft into those regions 
of the air which no human being 



What causes the bubbles made with hydrogen to rise 1 
What is said of the ascension of balloons % 



118 CHEMISTRY FOR BEGINNERS. 

has before penetrated. The heavens above him appear 
as if studded with silver upon a ground of black. The 
presumption of man might indeed lead him to attempt to 
make these aerial voyages to a much greater extent than 
has yet been done, he might even hope to be able to visit 
distant planets even in his earthly body ; but God has 
placed an eternal barrier in his physical constitution, 
which can endure the rarity and cold of the atmosphere 
but a few miles above the earth, and these constantly in- 
crease as we ascend. 

2. Hydrogen is highly combustible ; though it does not 
support combustion. 

A lighted candle placed under a jar 
of this gas, and with its flame immersed 
in it, is extinguished as you see in the 
figure. This is because there is no 
oxygen to support combustion ; for in 
this process, two things are always 
necessary, a combustible substance, 
and a supporter of combustion. Here 
then we have one, but not the other. 
When the candle is immersed in oxy- 
gen gas, it burns, because it is itself 
combustible, and it is surrounded by a 
supporter of combustion. 

The following figure shows hydro- 
gen itself burning ; the bottle contains 




What is a second property of hydrogen 1 
What does the figure represent ? 



BURNING OF HYDROGEN. 



119 



water, iron filings and 
weak sulphuric acid, the 
water immediately begins 
to be decomposed and the 
hydrogen to rise into the 
tube, which is fitted to the 
mouth of the bottle. On 
applying a lighted candle 
to the tube, the gas is in- 
flamed and burns as you 
see.* This is called the 
philosophic candle. To 
the ignorant, it might well 
afford matter for astonish- 
ment to see a bottle of wa- 
ter burning, and its pale, 
unearthly looking flame, 
might confirm their super- 
stitious belief that this 
phenomenon must be the 
effect of magic. But you 
can understand that the 
combustible substance, hy- 
drogen, being inflamed by the candle, and furnished with 
oxygen from the surrounding air, burns as oil would in 
the same situation. The figure on page 118, shows a 
flame at the mouth of the bottle ; this is the hydrogen gas 
which was set on fire by the flame of the candle, although 
this flame was itself extinguished on being wholly im- 
mersed in the gas. 




* The young ladies of the Seminary of Troy N. Y. who are in 
the habit of performing chemical experiments in their daily exer- 
cises and at the public examinations, have by means of a suitable 
apparatus, exhibited some splendid experiments, to illustrate the 
burning of hydrogen and carburetted hydrogen. 



How does it appear that hydrogen is combustible ? 
10* 



120 



CHEMISTRY FOR BEGINNERS, 




But what do you think is the product 
of this combustion of hydrogen ? You 
will perhaps be surprised to learn that it 
is water. If you hold a bell glass over 
the flame of burning hydrogen, you may 
see a moisture upon its sides, occasioned 
by the union of the hydrogen with the 
oxygen of the air. 



This figure presents you 
with another instance of the 
burning of hydrogen. You 
say — * we see nothing here 
but a common looking lamp, 
and candle.' The burning of 
lamps and candles is, howev- 
er, one form of the combustion 
of hydrogen. This may be 
proved by holding a tube for 
some time over the flame ; 
moisture will collect upon the 
sides of the tube. This moist- 
ure is formed by the union of 
oxygen and hydrogen. The 
oil and tallow furnish hydro- 
gen ; it is this which ren- 
ders them so combustible ; they contain also another 
combustible substance, carbon ; but it is the hydrogen, 



What is produced by the burning of hydrogen ? 
What causes the flame of lamps and candles 1 




PROPERTIES OF HYDROGEN. 121 

principally, which causes the flame. The air furnishes 
the necessary oxygen. 

3. Hydrogen when mixed with 
oxygen or atmospheric air, on be- 
ing inflamed, explodes like gun 
powder. The firing of the hydro- 
gen gun, in the lecture room of 
the chemist, often causes, both ter- 
ror and amusement. A vessel of 
tin is filled with a mixture of one 
part hydrogen to two of air ; a cork 
is then put into the open end. On 
applying a lighted taper to a small aperture, the gas in- 
flames, and expands so much as to drive out the cork 
with great force, accompanied by a loud report. 

From the explosive nature of hydrogen, it is thought 
that this gas is concerned in producing earthquakes. In 
the bowels of the earth are vast quantities of iron; water 
also exists in an equal proportion, filling chasms and fis- 
sures in the rocks. You have seen that when water 
comes in contact with iron, it yields its oxygen to the 
metal, and the hydrogen becomes a gas. You have also 
seen that when this gas is mixed with atmospheric air, if 
it comes in contact with a burning substance, an explo- 
sion takes place. Thus we may imagine that in the 
vast caverns which exist in the earth, hydrogen mingling 
with the air meets with something which inflames it; 
in the explosion which follows, the ground is thrown up, 
and in some cases whole cities are buried up in the 
chasms thus made. 

4. Hydrogen gas cannot be breathed by animals ; like 
nitrogen, however, it destroys life rather by excluding ox- 
ygen than because it possesses any noxious quality. By 

What is the third property of hydrogen 1 
"What reasons are there for supposing that hydrogen may be 
concerned in producing earthquakes '? 
What is a fourth property of hydrogen gas 1 



122 CHEMISTRY FOR BEGINNERS. 

a mixture of hydrogen and oxygen, an atmosphere might 
have been formed that would have supported life. But 
such a mixture we have seen is explosive, and would 
have been destructive to the foundations of the earth itself* 
We see, therefore, that He who formed and tempered 
these elements, knows best how to mingle and propor- 
tion them, that they may all perform a part in sustain- 
ing, instead of destroying his other works. 

Hydrogen gas exists in almost every compound sub- 
stance ; making a part in most fluids, as water, and every 
thing which contains water, and in all animal and veget- 
able substances. In minerals, especially coal, it exists 
in abundance. The wood which you see burn, owes its 
flame in part* to hydrogen, usually, however, combined 
with carbon, a substance yet unknown to you. The pale 
flame of wood is the hydrogen ; it is most abundant in 
green wood, while carbon is more plentiful in dry wood, 
and affords a richer and a deeper flame. The sulphur 
which exists in coal often gives it a bluish flame. Oil 
and tallow, as we have remarked, contain a great por- 
tion of hydrogen, which causes their combustible nature. 

Water, or Hydrogen and Oxygen united. 

Water is composed of 2 parts of hydrogen and 1 of 
oxygen ; that is when reckoned by bulk ;— in weight, 1 
part of hydrogen, and 8 parts of oxygen constitute water. 
This you can as easily understand, as that a quantity of 
feathers, occupying double the space of the same quantity 
of wool, might yet weigh but 1 pound, while the wool 
weighed 8 pounds.* The weight of the two elements, 
hydrogen 1, and oxygen 8, makes 9, which number 
represents water. It is important that you should recollect 

* It is not important that the relative specific gravity of wool and 
feathers should be here given correctly, but the case is merely 
stated for illustration. 



What is said of the difference of hydrogen 2 

What are the proportions of oxygen and hydrogen in water % 



ANALYSIS OF WATER. 



123 



that the combining weight of hydrogen is 1, while that 
of oxygen is 8 ; this circumstance having given rise to 
what is called the theory of atoms, respecting which, we 
have made some remarks in the chapter which treated of 
nitrogen and its compounds. 

The nature of water may be proved in two ways, anal- 
ysis or a separation into the two elements, oxygen and 
hydrogen ; and synthesis by which these two gases are 
combined and form water. 

Analysis of Water. 

When water in the state of steam is made to pass over 
heated iron, the metal absorbs the oxygen, and hydrogen 
gas escapes ; the iron will be found to have gained in 
weight 8 grains of oxygen for each grain of hydrogen 
that is obtained. This figure shows 

an apparatus by 
which steam is de- 
composed by pass- 
ing over hot iron. 
The iron tube to 
which the retort 
is cemented, is a 
gun-barrel ; to the 
opposite end of 
which is fitted a 
flexible, leaden 
tube, for the par- 
pose of conducting 
off the hydrogen 
gas that is to be 
obtained. With- 
in the gun-barrel, 
is introduced a 
quantity of small 
bits of iron, and 

How may the nature of water be proved 1 
How may steam be decomposed 1 
Explain the figure. 




124 CHEMISTRY FOR BEGINNERS. 

the glass retort is partly filled with water. A quantity 
of charcoal within the furnace being ignited, soon heats 
the gun-barrel to a red and then to a white heat. In the 
mean time a chaffing dish of burning coals is placed un- 
der the retort ; the water soon boils, is changed to steam, 
which passes through the gun-barrel and parts with its 
oxygen to the metal, while the hydrogen escapes through 
the leaden tube and may be collected. 

When water is subjected to the action of the galvanic 
circle, it will be decomposed, hydrogen will appear at the 
negative pole, and oxygen at the positive pole. The 

figure shows you how this 
I experiment may be perform- 
l ed. A glass tube, a, is filled 
with water, and corked at 
both ends ; the two wires of 
the galvanic circle are then put through the corks. The 
water being acted upon by galvanic electricity, its ele- 
ments separate, and hydrogen is attracted to the negative 
pole, and oxygen to the positive. You must now reflect 
a moment, whether this is because the gases have the 
same electricity as the poles to which they go, or 
whether it is because their electricities are opposite, 
Opposite electricities attract, while similar electricities 
repel one another. 




What effect has galvanism upon water 1 



FORMING OF WATER BY SYNTHESIS. 125 




Forming of Water by synthesis. 

We will now examine into the recomposition of water. 
* This apparatus consists of a glass globe, with a *neck 
cemented into a brass cap, from which three tubes pro- 



How may water be recomposed, or its elements united? 



126 CHEMISTRY FOR BEGINNERS. 

ceed, severally communicating with an air pump and 
reservoirs of oxygen and hydrogen. It has also an in- 
sulated wire fixed for producing the inflammation of a 
jet of hydrogen, by means of an electric spark. In 
order to put the apparatus into operation, the globe must 
be exhausted of air and then supplied with oxygen to a 
certain extent. In the next place, hydrogen is to be- 
allowed to enter in a jet. which is to be inflamed by an 
electric spark. As the oxygen is consumed, more is to 
be admitted.'* The explanation of this figure being 
given in the words of a learned chemist, the beginner 
may not understand it all, but this you can comprehend; 
that the glass globe is first exhausted of atmospheric air, 
then filled with oxygen gas ; and that a stream of burn- 
ing hydrogen is made to pass into the globe. The two 
gases thus unite by combustion, and form water. The 
simple mixture of the gases does not form water, but it 
is necessary they should be united while burning. 

Another apparatus for form- 
ing water by the burning of 
hydrogen is here represented. 
A current of burning hydrogen 
passes into the mouth of the 
tube a. The hydrogen in burn- 
ing unites to the oxygen of the 
lair, and the glass cylinder b 
€p*— ■ ■^^/-^ttwwi^ S0Qn a pp ears lined with vapour 

which condenses in drops. 
♦ Prof. Hare. 




What other experiment illustrates the formation of water 7 



RECOMPOSITION OF WATER. 



127 




This figure shows hydrogen burning 
in an atmosphere of oxygen ; a is a glass 
cylinder filled with pure oxygen ; b is 
a receiver of hydrogen immersed in a 
vessel of water c. When the stop cocks 
d d are opened, the hydrogen rises 
through the capillary tube and on 
being inflamed by an electric spark, it 
burns with great force, and drops of 
water soon collect in the cylinder. 

Water is called the protoxide of hy- 
drogen, because it consists of hydrogen 
united to one portion of oxygen. 

There is a deutoxide of hydrogen, 
sometimes called oxygenated water, but 
it is always the production of art ; its 
properties are very different from those 
of water ; it is corrosive to the skin and 
exhibits acid qualities. Here we see 
that one additional proportion of oxygen 
entirely changes the nature of water. 

The union of oxygen and hydrogen 
may be thus shown : 



Water, or the protoxide of hydrogen. 



Hydrogen. 



Oxygen. 



I 



Deutoxide of hydrogen. 

8 * 
x Oxygen. 

Hydrogen. g 

Oxygen. > 
Represented by 17. 



Represented by 9. 

Water exists in nature in the form of a transparent, 
colourless, inodourous liquid, capable of dissolving a 
great variety of substances. 

It becomes solid or ice at 32°, and assumes a gaseous 



What is illustrated by the figure 1 
Why is water called the protoxide of hydrogen '£ 
What is said of the deutoxide of hydrogen 1 
How does water exist in nature % 

11 



128 



CHEMISTRY FOR BEGINNERS. 




format 212°, occupying a volume 1700 times greater 
than in the liquid form. 

Freezing is the crystallization of water ; its crystals 
are usually confused, but their form is that of hexagonal 
(six sided) prisms. Water is a bad conductor of elec- 
tricity ; it refracts light strongly. 

Water is seldom found pure in nature ; in order to 
obtain it in this state, it must be distilled. The figure 

shows the manner in which this 
is done, a Represents a boiler 
of water in a furnace ; from b, 
the head of the still, the steam, 
which arises in boiling, passes 
into the worm, or spiral tube, 
where it is surrounded by cold 
w T ater in the cask d, this con- 
denses the steam, and drops of 
pure distilled water issue from the bottom of the tube. 
Distilled water is thought best for chemical experiments. 
Water in a solid form constitutes immense glaciers upon 
the summits of high mountains, and exists in vast quan- 
tities in the polar regions. The clouds and vapours of 
the atmosphere are water in a gaseous form. When 
condensed by cold, it solidifies, and being then heavier 
than the air, it falls in the form of hail, snow, or rain. 

Water was long considered as a simple element — it 
was not analyzed until the latter part of the eighteenth 
century. 

We have now considered the subject of Hydrogen 
Gas. Its most important properties are its inflammable 
nature, and its lightness or specific levity. Its most im- 
portant combination is water. 

At what temperature is water solid, and at what does it become 
a vapour ? 

What is said of the crystallization of water ] 

How may water be obtained pure % 

How extensively does water exist 1 

How long has water been known as a compound substance/? 

What are found to be the most important properties of hydrogen 
gas, and its most important combination % 




COMPOUND BLOW-PIPE. 129 

Blow-Pipe. 

We ought not to omit the mention of 
the compound blow-pipe, in which hydro- 
gen in connexion with oxygen is made of 
great use in Chemistry. But first we 
will teach you the construction and use of 
the common blow-pipe, which you here 
see represented. It is merely a simple 
brass pipe having a bulb in the middle, 
tapering, and bent at the smaller end ; it 
is used for impelling the flame of a candle 
or lamp upon any small substance, w<hich 
the chemist or mineralogist wishes to heat. 
Stones and ores, are said to be fusible 
when they can be melted in this manner. 

The compound blow-pipe or as it is sometimes called the 
Oxy-Hydrogen Blow-pipe is constructed in such a man- 
ner as to conduct through a small orifice the two mingled 
gases, oxygen and hydrogen, upon the substance to be 
melted; they are ignited as they pass out from the end of the 
pipe ; — this flame is found to be very powerful. Dr. Hare 
of Philadelphia, was the inventor of this important instru- 
ment, and the discoverer of the intense heat produced by 
the united power of the two gases, employed. In no 
other way, except by means of galvanic agency, can 
such an intense heat be produced. The compound blow- 
pipe has melted every mineral that has yet been subjected 
to its operation except the diamond, this is so inflammable 
that it burns without first melting. All the metals not 
excepting platina, gold, and silver, have been melted 
and burned by this blow-pipe. Wire, made of iron or 
copper burns in its flame, as a piece of cotton in an 
ordinary flame; earths burn with great brilliancy; 
a bit of a China cup under its influence burns with too 
strong a light to be borne by the naked eye. 



Describe the common blow-pipe. 

What is said respecting the compound blow-pipe ? 



130 CHEMISTRY FOR BEGINNERS. 



CHAPTER XII. 



Sulphur. Combination of Sulphur with Oxygen. Se- 
lenium. 

The new letter in the alphabet of Chemistry, which 
you are now to learn is Sulphur ; it differs from the el- 
ements we have examined in being found in a solid state, 
and existing in nature free from any combination, Sul- 
phur was known in very ancient times, and has long 
been in common use as a medicinal article, while oxy- 
gen, nitrogen and hydrogen, are words familiar only to 
chemists, because it is only by chemical analysis that 
they can be obtained. 

The word sulphur, is supposed to be composed of 
two Greek words, sol salt, and pur fire, so called from 
its great combustibility. 

Pure sulphur has never been decomposed, it is there- 
fore considered as a simple element ; but such is its af- 
finity for other substances that it is seldom found entirely 
pure with metals it forms sulphur ets and pyrites ; with 
oxygen it forms sulphuric acid; and this acid by its union 
with lime, soda, &c. forms sulphates. 

Sulphur is abundant in volcanic countries ; being com- 
bined with metals in the earth, it is separated from them 
by the heat of volcanoes, and becomes a vapour which 
rising from their craters falls again upon the surface of 



What new element are we now to consider, and why is its 
name more familiar than oxygen, nitrogen, and hydrogen % 
From what is the word sulphur derived 1 
What are some of the compounds formed with sulphur 1 
In what situations is sulphur usually found, and in what sub- 
stances is it contained 7 



SULPHUR. 131 

the earth, forming a crust, and sometimes beautiful crys- 
tals. It exists in some plants, as cabbage and dock, and 
in some animal substances, especially eggs. 

Sulphur is known in commerce in two states; the 
flowers or flower of sulphur and brimstone ; the latter is 
in the form of rolls, made by pouring melted sulphur in- 
to small moulds. The sulphur of commerce is gener- 
ally obtained by separating sulphur from some of its 
combinations. 

The sulphuret of iron parts with its sulphur on being 
sufficiently heated. 

Sulphur used for Bleaching 

The colour and odour of this substance are familiar 
to all. When sulphur is thrown upon coals, it rises in 
vapour and uniting with the oxygen of the air forms sul- 
phurous acid gas, which is very useful for bleaching 
straw and leghorn hats, and other articles. 

The process of bleaching straw, as practiced by mil- 
liners, you have probably observed. When carried on 
in a small way, the sulphur with a hot coal is placed in 
a dish upon the bottom of a barrel, and sticks are laid 
cross wise for the hats, or articles which are to be bleach- 
ed, to rest upon. The barrel is then covered with some 
thick cloth, to prevent the sulphurous acid gas which 
rises, from passing off. 

Iron moulds and the stains of vegetables may be re- 
moved in this way. Articles for bleaching must be wet 
with water. In the large Manufacturing establishments, 
where cotton cloth, yarn, and other articles on a great 
scale are to be bleached, they are hung wet upon frames 
in tight apartments, having floors of sheet lead, on which 
the sulphur is burned. 

In what two states is sulphur usually known ? 
What takes place when sulphur is thrown upon coals 1 
How do milliners bleach straw and leghorn hats 1 
11* 



132 CHEMISTRY FOR BEGINNERS. 

Other uses of Sulphur. 

The most important use of sulphur is in the compo- 
sition of gun-powder, in which it is mixed with charcoal 
and salt-petre. The effects of gun-powder are owing to 
the sudden change of the solids which compose it into 
gases. Sulphur is used in medicine externally to cure 
diseases of the skin, and internally as a cathartic. It is 
used to copy medals by being melted, and then poured 
into hot water ; in this state the medals are impressed 
upon it, and leave their impression. Small pine sticks, 
dipped in melted sulphur, form matches used for kin- 
dling fires. 

If a bar of hot iron is rubbed with a roll of brimstone, 
the iron will melt and fall to pieces. 

The figure shows 
a gun-barrel heat- 
ed to redness, hav- 
ing a piece of 
sulphur placed at 
one end, which is 
then closed. The 
sulphurous vapour 
issuing forth at an orifice near this end of the gun-barrel 
burns a bunch of iron wire which is held over it, so that 
it falls in melted globules. These are a sulphuret of 
iron, so called from being a combination of iron and 
sulphur. 

Beautiful crystals of sulphur for ornamental articles, 
may be made by melting it in a deep vessel. The sur- 
face will become solid ; this must then be broken and 
the liquid below turned off. 

Sulphur melts or fuses at 218° of heat. At 600° of 
heat, it sublimes ; that is, it becomes a vapour, and settles 

What are some of the uses of sulphur'? 
What is represented by the figure % 
How may crystals of sulphur be obtained ? 
What degrees of heat are required for melting and subliming 
sulphur % 




SUBLIMATION OF SULPHUR. 



133 



again on the sides of the vessel which is placed over it 
for that purpose. 

In order to obtain it purified from 
the earths, and metallic substances 
with which it is often combined, 
sulphur is distilled or sublimed in 
a vessel called an alembic, as here 
represented. The sulphur is put 
into the lower part, A, this is then 
placed over a vessel of sand B, cal- 
led a sand-bath, which is heated by 
a furnace C : by means of the sand* 
bath the sulphur is fusedrtnore grad- 
ually and equally, than could be 
done by placing it directly over a 
fire. When heated to a sufficient 
degree, the sulphur rises in the form 
of a thick, white vapour and settles 
in the head of the alembic, in clusters resembling flow- 
ers; from this has been derived the term flowers of sul- 
phur, though some from its fineness call it the flour of 
sulphur. Vessels of this kind are used in distilling, 
and the tube, which appears in the upper part of the 
alembic, is useful in conducting the distilled substance 
into a receiver. The product of sublimation is a solid, 
that of distillation a liquid. 

Sulphur possesses the positive electricity ; it therefore 
goes to the negative pole of the galvanic circle. 

The weight of its atom is reckoned as 16, hydrogen 
being unity, or 1. 




COMBINATIONS OF SULPHUR AND OXYGEN. 

We are now to consider sulphur as united with oxy- 



How is sulphur sublimed 1 

Why does sulphur go to the negative pole of the galvanic circle 1 
What is the weight of its atom % 

What two important substances are formed by the union of 
sulphur with oxygen 1 



134 CHEMISTRY FOR BEGINNERS. 

gen ; and here we find two important substances, sul- 
phurous and sulphuric acids. The ending in ous shows 
a lower proportion of oxygen, the ending in ic shows a 
higher proportion, 

Sulphurous Acid. 

We have already made some remarks upon the gas 
which results from the burning of sulphur in atmospher- 
ic air ; you will recollect that this is the sulphurous 
acid gas. One atom of sulphur, 16, is here united to two 
of oxygen, the sum of which being also 16, makes the 
equivalent of sulphurous acid 32. Sulphurous acid is 
obtained for observation in a class, by suspending burn- 
ing sulphur in a glass bottle containing a little water. 
The sulphurous acid gas uniting with the water gives it 
acid properties which may be ascertained by the taste, 
which is disagreeable and peculiar to this gas. By mix- 
ing blue vegetable infusions with this liquid it will be at 
first reddened and then the colour will be entirely de- 
stroyed. 

A red rose dipped in water containing a sufficient quan- 
tity of this gas loses its colour and becomes white ; pie- 
ces of calico which have been dyed with vegetable col- 
ours, become white on being wet with this liquid. But 
we have already spoken of the uses of sulphur in bleach- 
ing, or destroying the colours of different substances ; 
you will however observe, that it is only when combined 
with oxygen in the proportion to form the gas we are 
now considering, that it has this effect. 

In the ^hydrous state,* sulphurous acid is in the form 

* That is, without water. 



What is the equivalent number of sulphurous acid, and how 
may this be obtained in a liquid state 1 

What change is produced upon vegetable colours by immersing 
substances in sulphurous acid? 

How does sulphurous acid appear when not combined with 
water? 



SULPHURIC ACID. 135 

of a gas without colour, and having a strong smell. It 
is suffocating to the lungs, and destroys combustion. 

Sulphuric Acid, 

We have in sulphuric acid a combination of suphur 
with its highest proportion of oxygen ; or, 1 atom of sul- 
phur=16, united to 3 atoms of oxygen=24, makes the 
equivalent of sulphuric acid=40. 

This acid was formerly called oil of vitriol ; it has 
been known since the fifteenth century, and is now a 
very important article, not only in the laboratory of the 
chmeist, but in the manufacture of other substances. Ni- 
tric and muriatic acids are prepared by the assistance of 
sulphuric acid. 

Modes of obtaining Sulphuric Acid. 

Experiment. — You have seen that sulphur burned in 
atmospheric air does not unite with a sufficient portion 
of oxygen to form sulphuric acid ; neither if burned in 
pure oxygen gas will it form any thing more than sulphu- 
rous acid. In order to illustrate the formation of sul- 
phuric acid, four parts of sulphur being mixed with one 
of nitre (salt-petre,) may be burned in a glass bottle con- 
taining a little water, in the same way as for obtaining 
sulphurous acid. The water, though slightly sour, will 
exhibit the properties of weak sulphuric acid, and be 
very different as to taste from the sulphurous acid. 

In preparing this acid for commerce, large quantities 
of sulphur and salt-petre in the proportion of 8 of the for- 
mer to 1 of the latter, are burned in chambers lined with 
sheet lead. The mixture being placed in a vessel upon 

In what proportions does oxygen exist in sulphuric acid 7 
Has this acid been long known, and is it a useful substance % 
How may the formation of sulphuric acid be illustrated 1 
How are large quantities of sulphuric acid prepared for com- 
merce 1 



136 CHEMISTRY FOR BEGINNERS. 

the leaden floor, which has been covered with water, is 
inflamed ; in burning it consumes the oxygen of the air. 
New portions of the sulphur and salt-petre are added from 
time to time, and fresh air admitted into the chamber. 
The sulphuric acid gas is absorbed by the water upon the 
floor of the chamber ; this is afterwards distilled in order 
to obtain the acid in a pure and concentrated state. 

The explanation of this process is this : sulphurous 
acid is first formed by the burning of the sulphur in the 
air, the nitre furnishes another portion of oxygen, and 
the sulphurous thus becomes sulphuric acid. 

Some of the properties of sulphuric acid you have 
already learned — you have seen that many substances 
have so strong an affinity for it that they leave their eld 
combinations to form with it new ones. Thus muriate 
of soda, became sulphate of soda, and muriate of lime, 
sulphate of lime. As we proceed, we shall find that it 
unites with metals, forming substances called sulphates, 
while the sulphurous acid uniting with metals forms 
sulphites. 

Sulphuric acid is one of the most corroding substances 
in nature. I could show you a book, which now lies 
before me, that seven years ago happened to have one 
drop of this acid fall upon it ; at first it only made a 
brown stain, but it has continued to eat gradually until 
a great many pages have been partly consumed ; or, 
I should rather say, have been burned, since the effect 
is produced by the action of oxygen upon the paper, 
and indeed its appearance is exactly what it might have 
been, if burnt slowly by a hot coal. Thus in the course 
of time, one drop of this acid will consume the whole 
book. You will I hope be very careful in its use, should 
you attempt to perform experiments with sulphurous 



How is this process explained % 

Does sulphuric acid combine freely with other substances 1 
What instance is mentioned to prove the corrosive nature of 
sulphuric acid 1 



SULPHURIC ACID. 137 

acid, and not suffer it to fall upon your clothing, and 
especially any part of your person. 

But should such an event occur in consequence of any 
accident, you will remember that while water only 
serves to excite the acid to action, chalk, lime, or any 
alkaline substance neutralizes it, and of course alleviates 
its effects. When swallowed accidentally, chalk and 
magnesia are the best remedies. But every person who 
makes use of this, or any other active substances, should 
be very careful to have it conspicuously labelled. 

When sulphuric acid is decomposed by galvanism, the 
sulphur goes to the negative, and the oxygen to the pos- 
sitive pole. 

Combining Weight. 

It was mentioned that sulphur was considered as rep- 
resented by the number 16, it being so much heavier 
than hydrogen which is taken as a unit, or 1. Oxygen 
is 8 ; therefore the two acids we have been considering 
may be thus stated ; — sulphurous acid composed of 1 part 
sulphur 16, and 2 parts Oxygen 16=32. Sulphuric 
acid composed of 1 part sulphur 16, and 3 parts Oxy- 
gen 24=40. 

We see, that the number 32, stands for the lower acid, 
and 40 for the higher acid. 

We have now closed our remarks upon the compounds 
of sulphur with oxygen ; we shall hereafter notice sul- 
phates, sulphites, and sulphurets, which are compounds 
of sulphuric acid and sulphur with metals, alkalies, and 
earths. 



What are the most proper applications in case of accidents with 
sulphuric acid '\ 

When sulphuric acid is decomposed by galvanism, to which 
pole is each element attracted 1 

What is said respecting the combining weight of the atoms oi' 
sulphur &c, and of the numbers which stand for sulphuric and 
sulphurous acid ? 



138 CHEMISTRY FOR BEGINNERS. 

SELENIUM. 

Before closing this chapter we will introduce an ele* 
ment which being considered as simple, should not be 
omitted ; though little can be said of it to interest the 
beginner in Chemistry. Selenium was discovered in 
1817, by the Swedish chemist, Berzelius. It was by him 
considered as a metal ; but as it is found to be a bad con- 
ductor of electricity and caloric, which is not the case 
with the metals, it is not at present ranked as such. 

Selenium is found in connexion with various metals, 
as lead, silver, copper and iron. It was first discovered 
in iron pyrites, (sulphuret of iron,) which are used in 
Sweden for the manufacture of sulphuric acid. A red- 
dish substance was observed to remain, after the process 
for obtaining the sulphur was completed. On burning, 
a smell like that of horse-raddish was given off Ber- 
zelius found it to resist all attempts to decompose it, and 
therefore classed it among the elementary substances. 

Its properties in some respects resemble sulphur. — 
When powdered, its colour is reddish, but when broken 
in larger masses, its fracture is metallic. It is soft like 
wax. Its combinations are not numerous or important, 
at least as far as is now known respecting it. With ox- 
ygen it forms selenic and selenious acids. 



When and by whom was selenium discovered 1 
What circumstances led to its discovery? 
What are its properties 1 



PHOSPHORUS. 139 



CHAPTER XIII. 



Phosphorus. Impositions practiced by means of Phos- 
phorus. Eudiometer of Phosphorus. Phosphorus 
and Oxygen. Phosphorus and Hydrogen. 

We now commence the observation of another simple 
substance, which though less commonly known than the 
one we have last examined, constitutes a portion of pur 
own frame, it being found combined with other substan- 
ces in large quantities, in animal bones and teeth. 

The word Phosphorus is derived from the Greek 
words phos light, and phero to bear, and signifies light- 
bearer. 

Notwithstanding the existence of this substance is 
as ancient as the creation, it was not discovered until 
the year 1691, when Brandt, an alchemist of Germany, 
accidentally obtained it. The reason of its being so long 
unknown, is, that it is intimately combined with other 
bodies, and can only be separated from them by a long- 
process. 

Bones contain phosphorus united to oxygen and lime, 
forming a compound which is called phosphate of lime. 

The phosphate of lime consists of phosphoric acid 'and 
lime. In order to obtain pure phosphorus, the lime, and 



What substances contain phosphorus 1 
What is the word phosphorus derived from *? 
Has phosphorus been long known 1 
What substances contain the phosphate of lime? 
How may pure phosphorus be obtained from the phosphate 
of linie 1 

12 



140 CHEMISTRY FOR BEGINNERS. 

the oxygen of the phosphoric acid, must be disposed of. 
As you are not yet chemists enough to attempt the 
manufacture of this article, it is not necessary that you 
should study the operations which this requires ; these 
chiefly depend on that great principle of chemical affin- 
ity which we have endeavored to explain. First, one 
substance is attracted from the phosphorus by presenting 
another for which it has a greater affinity, and then the 
other substance is withdrawn in the same manner. 

Every lecturer who makes experiments in chemistry 
does not prepare the phosphorus he uses. This is ob- 
tained from the shops in the form of yellowish sticks, 
smaller than a pipe's stem and a few inches in length. 
It cannot be put up in papers and handled like most 
other solid substances which we purchase. It is usually 
kept in vials of water, because when exposed to the air, 
and the slightest increase of temperature, it takes fire. 

When you see phosphorus, that has for some time been 
kept in water, you may observe that the sticks are cov- 
ered with a whitish crust ; this is an oxide of phosphorus. 
It is formed by the attraction which this substance has 
for oxygen, which it takes from the water ; it is still 
more combustible than pure phosphorus. If exposed to 
the sun, it takes fire spontaneously. 

Impositions practised by the use of Phosphorus. 

In former times, wicked and and artful people imposed 
greatly upon the ignorant, by means of the peculiar prop- 
erties of phosphorus ; for instance, words written on a 
board, with a stick of this substance, will, in the dark, 



In what form is phosphorus usually obtained for chemical ex- 
periments *? 

What is the whitish crust that covers the sticks of phosphorus 1 

In what manner have impositions been practised upon people 

by the use of phosphorus 1 



EUDIOMETER. 141 

appear like the words of fire. It is said the monks of 
early days, who possessed nearly all the knowledge of 
chemical substances which then existed, sometimes prac- 
tised upon the credulous novice, by making him believe 
he saw the devil with flames about his head and ready 
to take possession of him if he refused to pronounce 
monastic vows. By dissolving phosphorus in oil and 
rubbing the face and hair with it, it produces, in the 
dark, the appearance of a glowing fire, playing over the 
features, and issuing from the head. It does not burn 
the skin, if the phosphorus be thoroughly mixed with 
the oil. # 

It is the great affinity which phosphorus has for 
oxygen that causes the phenomena, we have described ; 
this affinity is so great, that by uniting with its oxygen, 
phosphorus* burns when exposed to air of an ordinary 
temperature. The burning, or combustion, in this case 
is very slow, and is not painful or injurious to the skin. 
Inflamed in pure oxygen gas, phosphorus burns with 
the most vivid brilliancy. 

Eudiometer, or the 'purity of the air, tested. 

By the use of phosphorus, the purity of the air is 
tested in the following manner : — an instrument, called 
an eudiometer, which is represented on the next page, 
shows a glass matrass inverted in a jar of water ; a coil 
of wire supports a stick of phosphorus. By degrees 

* A fine young lad, the son of a distinguished chemist, was, a 
few years since, badly burned in consequence of a failure in this 
respect, when showing this property of phosphorus before a class 
of young ladies. Although he suffered much from pain he went 
through with the exhibition without complaint. 



What causes the phenomena which have been mentioned 1 
Describe the eudiometer. 



142 



CHEMISTRY FOR BEGINNERS. 



the phosphorus unites with all 
the oxygen of the air in the 
glass vessel, leaving- only ni- 
trogen, while water ascends to 
fill the place of the gas which 
has been absorbed. The quan- 
tity of oxygen which the air 
contained, is ascertained by a 
knowledge of the quantity of 
air which was included, and 
the' quantity which has united 
to the phosphorus ; for you 
must remember that none of 
the nitrogen is absorbed by 
it. When the air of any place 
is found to contain less than 
the usual proportion of oxy- 
gen, it is pronounced impure. 
The term eudiometer, is de- 
rived from the Greek, and sig- 
nifies health of the atmosphere. 

Substances which contain phosphorus, and its uses. 

You may well suppose that a substance so combusti- 
ble as phosphorus does not exist in a free state in nature ; 
it is always obtained by analyzing some of its com- 
pounds, usually the phosphate of lime. Combined with 
oxygen it enters into combination with many minerals ; 
it exists in the nerves and brains of fish, which on this 
account often have a luminous appearance in the dark. 

It is not an important substance as respects its applica- 
tion to the arts. It is used in making phosphoric matches, 
and as we have just seen in testing the purity of the air. 
Attempts have been made to use it in medicine, but its 
effect upon the animal organs is said to be injurious. 




Is phosphorus found in nature in a pure state 1 
b it of important use in the arts and in medicine ! 



PHOSPHORUS. 



143 




Combination of Phosphorus and Oxygen. 

There are two acids formed by the union of oxygen 
and phosphorus ; viz. phosphorous and phosphoric acids. 
1. Phosphorous acid ; this is obtained by the slow- 
combustion of phosphorus in the air; its properties are 
not remarkable. In combination with other substances 
it forms phosphites. 

2. Phosphoric acid ; this is obtained 
by the burning of phosphorus under 
a bell glass in oxygen gas. The bell 
glass containing oxygen, is set in a 
shallow vessel containing a little wa- 
ter, and the phosphorus is placed up- 
on a small cup raised from the bottom 
of the vessel. On being inflamed with 
a taper it burns rapidly and with great 
brilliancy. The bell glass, is filled 
with a white vapour resembling a snow storm in minia- 
ture ; white flakes then fall to the bottom of the vessel, 
these are phosphoric acid. 

The oxygen may be expel- 
led from this acid, and phos- 
phorus again obtained by 
heating it with charcoal.— 
The figure shows you a re- 
tort a, placed over a furnace b. 
The retort which contains 
phosphoric acid and charcoal, 
has its tube immersed in the 
basin of water c. Large 
quantities of gas, carbonic acid 
gas, which is composed of ox- 
ygen from the phosphoric acid, 
united to a gas which proceeds 

What two acids are formed by the union of oxygen with phos- 
phorus 1 
How is phosphorous acid obtained? 
How is phosphoric acid obiained? 
12* 




144 CHEMISTRY FOR BEGINNERS. 

from the charcoal, pass over. When the retort is at a 
red heat, phosphorus in the form of a reddish wax, 
appears in the basin of water. 

The weight of an atom of phosphorus, being in re- 
lation to the weight of an atom of hydrogen, 12 ; its two 
acids are thus expressed. Phosphorous acid; 1 part 
phosphorous, 12, and 1 part of oxygen, 8, this is repre- 
sented by the number 20. 

Phosphoric acid ; 1 part phosphorous ,12, and 2 parts 
oxygen, 16, this is represented by the number 28. 

Combination of Phosphorus and Hydrogen. 

In combination with hydrogen phosphorus forms a 
substance called phosphuretted hydrogen. 

Here we have two simple combustible substances united. 
You will observe that the termination uret or uretted is 
used to denote this union. 

Phosphuretted hydrogen may be obtained by heating 
phosphorus with a solution of potash, and collecting it 
through a solution of the same kind, instead of water. 



How may phosphorus be obtained from phosphoric acid 1 
By what numbers are the acids of phosphorus expressed 1 
What substance is formed by the union of phosphorus with 
hydrogen % 

What does the termination uret denote 1 
How is phosphuretted hydrogen obtained?- 



PHOSPHORUS. 145 

Part of the phosphorus unites with the potash — hydro- 
gen is given off from the solution, and unites with anoth- 
er portion of phosphorus, forming phosphuretted hydro- 
gen gas. This gas passing from the beak of the retort 
into the solution of potash rises into air, where it in- 
flames spontaneously. Each bubble of gas after explo- 
ding ascends in the form of a pale wreath of smoke be- 
coming fainter and larger as it rises. 

This gas is produced in nature by the decomposition of 
animal substances in which the two elements exist abund- 
antly; particularly in the brain sand nerves. Thus when 
a body is buried, as the animal matter putrifies, hydrogen 
and phosphorous in a gaseous form escape and uniting 
pass up through the earth, and ascend into the atmos- 
phere ; owing to the peculiar nature of this gas, it takes 
fire at the ordinary temperature; thus it happens that over 
grave yards, lights are sometimes seen, which, the igno- 
rant are ready to believe are the spirits of the departed, or 
indicative of some unearthly visitation. Children not 
unfrequently hear about J ack-c? -lanterns, or wandering 
spirits which lead people into bogs and marshes and then 
disappear. It is in damp grounds that the phosphoret- 
ted hydrogen is most likely to be formed, and we can 
therefore see the reason for the Jack-o'-lantern leading 
its followers into such places. Professor Silliman says, 
I ■ travelling once through a deep valley in a dark night, 
; I was surrounded by multitudes of pale, lambent lights ; 
I they were every moment changing their position and 
some of them were within reach of my whip/ 

You see how knowledge serves to remove from the 
\ mind those superstitious fears which torment it, when ig- 
* norant of the causes of the phenomena of nature. It 
; was this ignorance which gave rise to a belief in the ex- 
istence of witches and hobgoblins of various kinds. By 
means of knowledge man has subjected the elements of 

How may the lights be accounted for which often appear in 
damp grounds, grave yards, &c. 

What are some of the effects of knowledge 1 



146 CHEMISTRY FOR BEGINNERS, 

nature to his sway; and although no witches ride through, 
the air on broomsticks, yet people do fly in balloons, 
ride with almost the rapidity of lightning in rail road 
cars, or glide, with the swiftness which might be ascri- 
bed to the motion of spirits, in steam boats. All this is 
the effect of knowledge. 



CHAPTER XIV. 

Carbon — Cabonic Acid, and Carbonic Oxide. 






The subject of our lesson is Carbon; the word is de- 
rived from carbo a coal. This exists in all vegetable and 
animal matter, being one of the most extensively diffused 
substances in nature. 

You are familiar with charcoal ; you know it is what 
remains of wood after it has been exposed to heat. The 
common charcoal which is used in household operations 
is made by placing sticks of wood in a conical pile, cov- 
ering them with earth, and kindling a fire in an opening 
below. The volatile parts of the wood are driven off by 
heat and make their way through apertures in the cov- 
ering, and charcoal remains. This is nearly pure car' 
bon. 

Diamond. 

In the diamond you may see pure, crystalized carbon. 
But diamonds are very rare in our country. There is a 
great deal of jewelry which is made in imitation of dia- 

What element is the subject of this lesson, and where does it 
exist i 
What is charcoal, and how is it obtained ? 



DIAMOND. 



147 



monds, but the real diamond possesses a splendour that 
cannot be imitated. The empress Catherine of Russia, 
gave 100,000 pounds for a diamond about the size of a 
pigeon's egg, which was placed in the imperial sceptre. 

Sir Isaac Newton suggested that the diamond might 
be made to burn, because its power of reflecting and re- 
fracting the rays of light was so great ; and where a 
body was capable of producing such effects on light, he 
thought it must be affected by caloric. It is now proved 
that the diamond is a combustible substance. 

This figure showsan 
apparatus for burning 
diamonds, a, is a small 
tube, which is to convey 
a stream of hydrogen 
upon the diamonds 
which are placed in the 
little platina grate b ; at 
ee, are two wires which 
are designed to inflame 
the jet of hydrogen by 
communicating electri- 
city, which they receive 
from a machine by 
means of a ball, d, in 
which they terminate. 
When the apparatus is used, the diamonds being placed 
upon the platina grate, the glass globe which surrounds 
it is first exhausted of air by means of an air pump, and 
then filled with pure oxygen ; sparks of electricity are 
now communicated to the ball connected with the wires, 
and a current of hydrogen thrown up by turning a 
stop cock, and pressing a bladder which contains this 
gas. The platina dish and the diamonds are first heated 




&^ 




Whet is the real diamond composed of, and what is said of its 
value 1 

What led Sir Isaac Newton to think the diamond might be 
made to burn 2 . 



148 CHEMISTRY FOR BEGINNERS- 

to a white heat, and then the diamond begins to burn. — 
The stop cock is now turned to prevent the passage of 
more hydrogen, and the diamonds will continue to burn 
till consumed. The product of this combustion of dia- 
monds in pure oxygen is carbonic acid gas. This exper- 
iment proves that the diamond is composed of carbon. 

You might suppose that since chemists know of what 
they are composed, and as this material is very abundant 
in nature, they could manufacture diamonds ; but you 
must recollect that they are crystals of carbon, and no 
method of bringing carbon to this state is known. 
Scientific men, stimulated by the desire of making dis- 
coveries, and artists eager for wealth have sought 
to ascertain a mode of crystallizing carbon, but like 
the alchymists of former days, who endeavoured to turn 
stones into gold, they have been disappointed in the 
attempt to make diamonds from charcoal, although the 
substances which compose them are the same. 

You must not confound with charcoal the various 
kinds of coal which are dug out of the earth ; the latter 
are called mineral coal. They contain a large propor- 
tion of carbon, but usually mixed with some sulphur 
and iron. They are heavier than charcoal. 

Black lead or plumbago, lamp black, and soot are 
chiefly composed of carbon. 

In considering the properties of carbon, we shall 
confine ourselves to that form of it which is seen in 
charcoal. 

1. It is remarkable for its power of absorbing 
gases of different kinds, and giving them off again 
when heated. When newly made, its pores become 
filled with the first kind of air or gas which comes in 
contact with it. In order to purify it from these sub- 



Describe the process for burning diamonds. 

Can diamonds be manufactured from carbon 1 

Are all kinds of coal called charcoal 1 

What substances besides coal are chiefly composed of carbon ? 

What is said of the absorbing power of charcoal % 



CHARCOAL. 149 

stances it must be heated, when it is again ready to 
absorb other gases. These gases do not form a chemi- 
cal combination with charcoal, or alter either its prop- 
erties or their own 5 for when driven off by heat and 
collected, they are found to be unchanged, and to leave 
the charcoal so. 

2. A very important property of charcoal is that of 
destroying the smell, taste, and colour of many substan- 
ces. It is one of the most important antiseptics* known. 
It will purify water that has become putrid, and for this 
reason is very useful to persons at sea, who cannot 
obtain fresh water. Tainted meat may be made sweet 
by being boiled with powdered charcoal, or rubbed 
thoroughly with it. But the house-keeper who uses it 
for this purpose must remember that it must be heated 
to redness, and applied to the meat before it has absorbed 
other gas than the putrid odour of the meat If put into 
water while hot, it may be thus preserved fit for use. 
On account of its antiseptic nature, it makes an excellent 
dentriflce. 

3. Charcoal resists decay ; for this reason the ends of 
posts which are to be put into the ground are charred or 
burnt. Silliman remarks, that he saw in the British 
Museum, at London, a pointed stake, which, with many 
others, was found in the bed of the Thames, in the spot 
where, according to the Roman historian, Tacitus, the 
Britons fixed a vast number of such stakes to prevent 
Julius Caesar from passing with his invading army. 
They were all charred to a considerable depth, and 
retained their form entirely; they were so firm that knife 

* Antiseptic is derived from the Greek anti, against, and septo, 
toputrify; an antidote to putrefaction. Whatever possesses the 
power to prevent animal substances from putrefaction, or removes 
it after it has commenced, is called an antiseptic. 

What is said of the purifying power of charcoal 1 
Why are the ends of posts sometimes charred, or burned before 
they put into the ground % 



150 CHEMISTRY FOR BEGINNERS. 

handles were manufactured from them, and sold at a 
great price. 

Uses of Carbon. 

Charcoal in the form of lamp black, is used with oil 
for paints, and printer's ink; with iron it forms steel ; 
with sulphur and nitre it makes gunpowder. It is in 
common use for fuel, and especially in cooking opera- 
tions of various kinds. The diamond furnishes not only 
the most elegant ornaments, but is useful in the arts ; 
Jx is the best substance known for cutting glass. 

Combination of Carbon and Oxygen. 

We here meet with a gas which exists in a vast 
number of substances, which we throw out of our lungs 
at every breath, and yet which we cannot inhale in any 
large quantity without destroying life ; this is carbonic 
acid gas, sometimes called fixed air, because it exists in 
a fixed state in lime and many other minerals. 

Modes of obtaining carbonic acid gas. 

By burning diamond or charcoal in oxygen gas, pure 
carbonic gas is obtained. But the burning of diamonds 
is too expensive an operation to be performed except for 
important experiments, and the gas can be obtained still 
more easily than by burning charcoal in oxygen. 

There are in nature many carbonates ; that of lime 
under varions forms, as limestone, marble and chalk is 
the most common. Carbonates are composed of carbon- 
ic acid gas, united to some substance called its base ; 
thus lime is the base of carbonate of lime. 



What are some of the uses of charcoal 1 

What gas is it which we exhale in breathing, but which cannot 
be inhaled in any large quantity 1 

Is carbonic acid usually obtained by burning either diamonds or 
charcoal in oxygen gas 1 

What are limestone, marble, and chalk 1 



CARBONIC ACID. 



151 



The common method of obtaining carbonic acid gas is, 
by the decomposition of chalk or powdered limestone, by- 
means of sulphuric or muriatic acid. 

In the figure, the bottle a is supposed to contain pieces 




of marble or any other carbonate of lime ; through the 
tunnel b, is poured weak muriatic or sulphuric acid — >a 
violent effervescence takes place owing to the escape of 
carbonic acid, which passes through the tube c into the 
bell glass d ; the receiver is not filled with water, w ith 
which carbonic acid gas would unite ; but it excludes 
the common air. Carbonic acid seems held to its bases 
by a tie which is easily broken, for there are few acids 
which will not expel it from its combinations — thus 
vinegar poured upon pearlash, which is a carbonate of 
potash, causes the carbonic acid to pass off; its escape is 
indicated by the effer vesence that takes place. This is o w- 
ing to elective affinity. The acid which makes vinegar is 
called acetic acid, for this, the potash has a greater affinity 
than for the carbonic acid which is expelled. 



What is the common mode of obtaining carbonic acid gasl 
Is carbonic acid easily separated from its gases'? 
13 



152 CHEMISTRY FOR BEGINNERS. 

By means of heat only, the carbonic acid may be driven 
off from carbonates. Thus quick lime, which is used for 
white-washing and plastering is made from limestone, 
by heating the latter in kilns, and thus expelling the car- 
bonic acid gas. 

Properties of Carbonic Acid Gas. 

No animal can live in an atmosphere of this gas. In- 
sects, to be preserved, may be confined in it, as they will 
die at once. It is different in its effects upon the 
lungs from nitrogen or hydrogen, they do not support 
life, carbonic acid destroys it. In the two former, ani- 
mals die for the want of oxygen, in the latter they are 
killed. It is on account of the deadly nature of this gas, 
that charcoal is so dangerous when burnt in a close room. 
The small portable furnaces which are now so much in 
use for cooking, ironing, and other household operations, 
should never be used except in the open air, or in a fire 
place, and then the doors of the room should be opened. 
Three young women a year or two ago, were ironing in 
a close room, with furnaces to heat their irons, and all 
of them fainted successively. The charcoal, as it burns, 
gives off carbon, which, uniting with the oxygen of the 
air, forms carbonic acid gas. 

Carbonic acid gas does not support combustion ; a 
lighted taper suspended in it is immediately extinguished. 
This fact should be known to all ; — lives are often de- 
stroyed in consequence of people going into wells and 
vaults where this gas abounds ; sometimes when one 
person faints others go immediately into the same place, 
and many lives are thus lost in consequence of ignor- 
ance, If people would first test the purity of such places 
by suspending into them a lighted candle, they would 
at once know whether they could live in them ; — if 

How is quick lime manufactured ? 
Will an atmosphere of carbonic acid gas support life 1 
How can thf 
other places? 




CARBOLIC ACID. 153 

the air will not support combustion, it will not support 
life, or rather if it destroys the one, it will destroy the 
other. 

Carbonic acid gas is heavier than atmospheric air ; 
this is the reason why it is most abundant in low places. 
It sinks into them. 

It may be poured from one vessel to an- 
other like liquids. If you collect this gas 
in a tumbler it may stand without being 
covered, for it will not rise and escape like 
most other gases. It is a curious experi- 
ment to see a lamp extinguished by hold- 
ing over it what appears to be an empty 
tumbler ; for carbonic acid gas is without 
colour and invisible, yet it may be thus 
poured out upon a flame, and it will de- 
stroy it as if it were so much water. 

This gas is called carbonic acid, because it gives to 
liquid substances an acid taste of a peculiar kind, which, 
though not sharp, is lively and refreshing. It is this 
gas which sparkles and bubles in good bottled cider and 
some wines. It causes the effervesence and refreshing 
taste of soda waters, and the smartness of the Saratoga 
and some other mineral w 7 aters. 

Carbonic acid gas unites with water and imparts to it a 
peculiar taste. The soda fountains, in which carbonated 
water is prepared, are sometimes constructed as you see in 
the next figure. Pieces of pounded chalk or marble are 
put into a vessel* and sulphuric acid poured upon them ; 

* Having shown the manner in which the gas is obtained, it is 
unnecessary to have the whole apparatus here exhibited. The 
pipe B, is supposed to communicate with the vessel from which 
the gas issues. See the figure on the next page. 



Why is this gas most abundant in low places 1 
How can it be proved that carbonic acid gas is heavier than 
atmospheric air 1 

Why is it called carbonic acid gas 1 
How are soda fountains constructed 1 



154 



CHEMISTRY FOR BEGINNERS. 




the carbonic acid gas rapidly escapes into the tube B ; 
at A, is a part of the apparatus called a condenser which 
draws in the gas from the pipe B, and forces it through 
the other pipe C, into a vessel containing the water. By 
means of pressure, water is made to absorb large quanti- 
ties of this gas ; when sufficiently impregnated with it, 
the water is drawn out by means of the syphon or bent 
tube D, and flows into the tumbler, where it appears 
sparkling and foaming. This is improperly called soda- 
water, since it usually contains no soda. 

The peculiar properties of yeast or emptyings are ow- 
ing to this gas. In struggling to escape through the 
wet flour, or dough of which bread is made, the carbonic 



Why do yeast and pearlash make bread and cakes light ? 



CARBONIC ACID. 155 

acid gas becomes entangled and causes the little cavities 
which appear in light bread. Pearlash makes cake 
light, on account of the carbonic acid gas which it con- 
tains. 

Existence of this gas in nature. 

Carbonic acid gas forms nearly half of the marble and 
limestone which are so abundant in the mineral king- 
dom, forming beds and mountains ; — it is thrown from the 
lungs of animals in breathing ; — it is produced by the fer- 
mentation of liquors, and the burning of candles, lamps, 
furnaces, and fire-places. Oysters and other shell fish 
have a covering of carbonate of lime, which seems to be 
formed from matter partly furnished by their own bodies, 
and partly by the. salt water. 

It would seem as if so deadly a gas, as we find the 
carbonic acid to be, in its effects upon animal life, and 
produced as it is, in such great abundance, from the 
breathing of animals, the decomposition of substances, 
and the burning of candles and fires, would soon de- 
stroy the whole animal creation. Besides, we use oxy- 
gen at every inspiration or drawing in of the breath ; — 
does it not seem alarming to think of the great quantities 
of the deadly air w 7 hich is every moment formed, and 
the vast portions of the vital air which are at the same 
time consumed ? Behold here the wisdom of God, who, 
when he formed the gra?s, the herb and tree, and gave 
them to man for meat, so made them, that in their growth, 
they should absorb and be nourished by this very gas, so 
fatal to the life of animals : and, at the same, time throw 
from their vegetable lungs, that gas, without which, they 
would instantly die ! Truly, God gave the vegetable 
world for meat, in more senses than one ; and well might 
He, in beholding his work, and its curiously balanced 
machinery, pronounce it * good ! ' 

Is carbonic acid gas found extensively in nature 1 
Why does not the accumulation of carbonic acid, and the coQr 
slant waste of oxygen, destroy the whole animal creation ? 

13* 



156 CHEMISTRY FOR BEGINNERS. 

The weight of an atom of carbon is reckoned as 6, 
that of hydrogen being 1. 

Carbonic acid being composed of carbon 1 atom=6 

oxygen 2 " 16 

The number which represents it is 22 
This is called its chemical equivalent. 

Carbonic oxide gas. 

There is a combination of carbon with oxygen, called 
carbonic oxide ; in which the proportion of carbon is 
much greater than in the gas we have been studying ; 
indeed, the term, oxide, denotes that the substance con- 
tains less oxygen than is required to form an acid. 

Carbonic oxide is no less fatal to animal life than 
carbonic acid. The great chemist, Sir Humphrey Davy, 
of England, who often exposed his life, in his zeal for 
making discoveries, once attempted to inhale it, mixed 
with one fourth part of common air, but the attempt had 
nearly proved fatal. Another person, attempting to 
breathe it, appeared to fall into an apoplexy, from which 
he was restored by inhaling oxygen gas. You see how 
much men of science expose themselves, that they may 
learn the nature and properties of substances ; — and un- 
less they did so, of how many facts should we now be 
ignorant that are of importance to the world. 

You will recollect that 22 is the representative num- 
ber of carbonic acid. Carbonic oxide being composed 
of one part of carbon 6, united to one part oxygen 8, 14 
is the representative number of this gas ; — one additional 
part of oxygen, being 8, would change it into carbonic 
acid gas. 

What is the weight of an atom of carbon 1 
What is the chemical equivalent of carbonic acid 1 
What combination is there of carbon and oxygen besides the 
one we have just been examining? 
What is the effect of carbonic oxide when taken into the lungs % 
What is the representative number of this gas 1 



CARBONIC OXIDE. 



157 



Carbonic oxide is obtained by heating chalk and iron- 
filings to a red heat. The chalk furnishes carbonic acid, 
but the iron, having a great affinity for oxygen, takes 
some portion of it from the carbonic acid, and reduces it 
to carbonic oxide. The two gases pass off together, but 
by washing them with lime water, all the carbonic acid 




How is carbonic acid obtained 1 



158 CHEMISTRY FOR BEGINNERS. 

unites with it, forming carbonate of lime, while the car- 
bonic oxide is left in the state of a pure gas. The figure, 
on the last page, represents an invention of Dr. Hare 
for separating the two gases, by means of lime water. 
The gun-barrel, and furnace for heating the chalk and 
iron filings is not here described, but the pipe P is sup- 
posed to communicate with a reservoir of the mixed 
gases ; that is, the carbonic acid and carbonic oxide. 
The gases are introduced into the upper bell glass C, 
by turning a stop-cock which is between that and the 
pipe P. The lower pipe D, communicates with the 
bell glass A, and has, affixed to it, a gum elastic or In- 
dian rubber bag. The two gases, carbonic acid and 
carbonic oxide, are now introduced into the bell glass 
C, which had been previously filled with lime water ; 
this, as the gas enters from the pipe, sinks into the lower 
bell glass. By means of pressure from the hand, upon 
the gum elastic bag, jets of lime water are thrown up 
into the gas in the upper bell glass. All the carbonic 
acid unites with the water, while the carbonic oxide is 
left pure, and may be transferred into any receiver by 
means of the pipe. 

Carbonic oxide will not support combustion ; 
but it is inflammable, and will, itself, burn in 
oxygen or in common air. But the product 
of its combustion is not water as in the case 
of hydrogen ; it is carbonic acid. You may 
here see an inverted jar, placed over a ves- 
sel of carbonic oxide which is burning in 
a jet, as it issues from the tube, at the mouth. 
The inverted jar will be filled with carbonic 
acid gas. The air furnishes another atom of 
oxygen (8) which, uniting with the carbonic 
—J oxide, (14), makes carbonic acid (22). 



Describe Dr. Hare's invention for obtaining carbonic oxide 
pure? 

When carbonic oxide gas burns in air or water, what is the pro- 
duct of this combustion ? 




BORAX. 159 



CHAPTER XV. 



Boron. Iodine. Fluorine. Bromine. 

There is a substance known in commerce by the 
name of borax ; it is found abundantly in various parts 
of Asia, especially in the East Indies, from whence it is 
exported to Europe in large quantities, under the name 
of tincal. It is found in crystalline masses, resembling- 
alum, a yard, or more, beneath the surface of the earth, 
sometimes obtained by evaporating the waters of certain 
lakes, or found in a solid form at the bottom of lakes ; 
which is the case in the salt lakes of Peru. 

But borax is a compound substance, consisting of an 
acid called boracic * acid, — united to soda as its base ; it 
is a borate of soda, and is classed among the salts. 

In 1702, a chemist in Paris, discovered in borax, the 
boracic acid. It is obtained by adding sulphuric acid, 
to borax or the borate of soda. 

Experiment. — A small piece of borax is put into a ves- 
sel, and hot water and sulphuric acid poured upon it ; 
it is then placed over burning coals for a few minutes. 
The borax decomposes, and a sulphate of soda is formed ; 
this is in solution — on cooling, solid scales, of a white 
and shining appearance may be collected; these are 
boracic acid. 

* Pronounced borasic. 



Where is borax found ? 

Is borax a simple substance 1 

What acid is obtained from borax ^ 

By what process is boracic acid separated from borax 7 



160 CHEMISTRY FOR BEGINNERS. 

Explanation. — You will at once perceive here the 
agency of elective affinity ; the soda having a greater 
affinity for sulphuric than for the boracic acid, unites 
with it and expels the latter. 

But boracic acid itself is a compound ; its base was 
discovered about one hundred years after the acid it- 
self, by Sir Humphrey Davy. He found by heating the 
acid with a metal called potassium, that oxygen was 
liberated, and a dark, olive coloured mass remained. 
This he named boron, and as no succeeding chemist 
has been able to decompose it, it is ranked among the 
elements, or simple substances. 

The weight of its atom is 8, the same as oxygen. In 
boracic acid, 1 part of boron 8, is united to 2 parts of 
oxygen 16; this makes the representative number of 
this acid 24. 

Boron is a combustible substance, resembling carbon 
in some respects — the product of its combustion when 
burnt in the common air, or in oxygen gas, is boracic 
acid. 

The figure, p. 161, shows the apparatus lately invented 
by Dr. Hare, for the purpose of obtaining boron from bo- 
racic acid ; this acid, in a very dry state, is put, with 
the metal potassium, into a copper cup, supported by a 
cylinder of copper C ; — A, A, are the rods which sup- 
port the large receiver that is placed over the cup con- 
taining the boracic acid and potassium. One of the 
pipes P, communicates with an air pump. The air be- 
ing exhausted under the receiver, an iron heated to 
redness, is introduced through the cylinder B, until it 
touches the bottom of the cup above the tube C, which 

How is this explained'? 

How did Sir Humphrey Davy discover that boracic acid is a 
compound substance 1 

What is the weight of an atom of boron, and what is the repre- 
sentative number of boracic acid 1 

What is the product when boron is burned in oxygen or com- 
mon air. 



BORACIC ACID. 



161 



contains the boracic acid and potassium. When the cup 
is heated sufficiently, a deep red flame appears to cover 
the whole mass. On cooling, it is found that the potas- 
ium has taken from the acid its oxygen, forming the 
oxide of potassium, (or potash) while pure boron remains. 




Describe the apparatus of Dr. Hare for obtaining boron, 



162 CHEMISTRY FOR BEGINNERS. 

Boracic acid, dissolved in alcohol, burns with a pe- 
culiar flame, the edges and top being of a beautiful green 
colour. 

Uses of Borax. 

Borax is used in the arts, to assist in the melting of 
metals and other substances, with some of which, it forms 
various coloured glass. It has been used in medicine, 
as a remedy for sore mouths, especially in the case of 
infants. 

Iodine. 

Boron, we found to be a combustible substance. Io- 
dine, which we shall now consider, is ranked among 
the supporters of combustion ; that is, though it does not 
burn, it is supposed to promote the burning of other 
substances. 

All combustible substances possess the positive elec- 
tricity, while the supporters of combustion, possess the 
negative electricity. Hitherto we have examined but 
one supporter of combustion, viz : oxygen, and this, for 
a long time, was considered the only one. 

Iodine has been known only since the year 1812. It 
was discovered in Paris, by a manufacturer of soda, as 
he was burning sea-weeds to obtain this substance. 

It exists in the form of a solid, of a gray colour ; it 
is remarkable for its passing from a solid state imme- 
diately to that of a vapour, by a small increase of tem- 
perature. Almost every solid becomes a liquid before 



What is the appearance, when burning, of boracic acid dis- 
solved in alcohol 1 

What are some of the uses of borax 1 

In what important particular does iodine differ from boron 1 
What is remarked of the electricity of combustible substances 
and supporters of combustion ? 

When and by whom was iodine discovered 1 

In what form does it exist, and for what is it remarkable 7 



IODINE. 163 

it becomes a vapour; but this springs into vapour at 
once, or if it exists at all in a liquid state, the change is 
so sudden from that to a gaseous state, that it is not 
perceptible. 

The name iodine, is from the Greek iodes, signifying 
violet-coloured. This is the colour of its vapour, which 
appears very beautiful when seen through a clear, trans- 
parent glass vial or bulb. Every one who can obtain 
at a druggists, a small piece of iodine, can, by putting 
it into a vial, have the pleasure of examining the curious 
effects which the heat of a common lamp almost instantly 
produces, since it is an experiment unattended with diffi- 
culty or danger. As soon as the vapour of iodine is 
withdrawn from heat, it returns immediately to its solid 
state, and gray colour, without appearing to have un- 
dergone any change in its nature. 

Properties of Iodine. 

Its odour is very disagreeable — its taste acrid. It is 
very corrosive, eating quickly through a cork, if a bottle 
containing it, is stopped by one — -for this reason, glass 
stoppers are used. Its vapour is heavier than that of 
any other vapour ; it being about nine times heavier than 
the air. The weight of its atom is 124. It destroys 
vegetable colours. With starch it produces a blue 
colour, a circumstance which always shows its presence. 

Combinations of Iodine. 

Iodine unites with oxygen, forming iodic and iodous 
acids, with hydrogen, forming hydriodic acid, and with 
metals, forming iodides. With soda, lime, and other 
alkalies, it forms iodates. 

What is the colour of the vapour of iodine, and what does its 
name signify % 

What are some of the properties of iodine ? 
What combinations does iodine form with other substances % 
14 




164 CHEMISTRY FOR BEGINNERS. 

Method of obtaining Iodine. 

The figure shows a 
flask a, which contains 
crystals formed by evap- 
orating the ley of sea- 
weed ashes. Sulphuric 
acid is poured into the 
flask, and on the appli- 
cation of a gentle heat, 
the violet-coloured va- 
pour of iodine, rises in 
the head b, and passes through the tube into the receiver 
e, where they are condensed into the solid gray substance, 
iodine. 

Fluorine. 

You will perhaps smile when you learn, that chemists 
have placed among the elements, a substance which does 
not exist, or, at least, which has never yet been obtained; 
the name which they have given to this imaginary ele- 
ment is fluorine. 

There is a beautiful mineral found in England, called, 
from the place where it is the most common, Derbyshire 
spar. It is sometimes called fluor-spar ; fluor, because 
it melts easily, and spar, on account of its appearance 
being similar to that of minerals which are called spars, 
or sparry. Fluor spar is found to consist of lime united 
to an acid, which is named fluoric acid ; therefore the 
chemical name for fluor spar is fluate of lime. 

But you wish to know, why we imagine the existence 
of a substance called fluorine. You remember that bo- 
racic acid has been found to consist of a base, called bo- 
Describe the mode of obtaining iodine 1 

What imaginary substance do chemists class among the ele- 
hisntsl 

What is fluor-spar 7 

Why is fluorine supposed to have an existence 1 



FLUORINE. 165 

ron, united to oxygen : and that carbonic acid is composed 
of a base, carbon, united to oxygen, and so of all the 
acids we have noticed ; they all consist of a base united 
to an acidifying substance. Reasoning therefore from 
analogy, chemists have thought that fluoric acid must 
also be a compound, consisting of a base united to oxygen, 
or some other acidifyer ; this imaginary base has re- 
ceived the name of fluorine, because it is thought, in 
some respects to resemble idoine, and some other sub- 
stances ending in ine, which we shall soon examine. 
We shall not attempt to say any thing about this fluorine, 
which, like the hero of a novel, is but an imaginary 
thing. Fluoric acid has hitherto resisted all attempts 
to decompose it, so that, if fluorine does exist, it is so 
well satisfied with the companion to which it is united, 
that no temptations can induce it to separate. 

Method of obtaining Fluoric Acid. 

Experiment. — Fluoric acid 
is obtained in the state of a 
gas, from fluor spar,„by means 
of elective affinity. For this 
purpose, sulphuric acid is 
poured upon pulverized fluor- 
spar. Heat is applied, and the 
fluoric acid gas immediately 
begins to ascend. The figure 
represents an apparatus for 
collecting this gas. It must be of silver, as glass would 
not answer, for reasons we shall soon mention. The 
fluor-spar and sulphuric acid are put into the flask a, the 
gas passes through the tube b into the receiver c. 

Explanation. — Fluor-spar, or the fluate of linie, con- 
sists of lime and fluoric acid. Lime has a strong 
affinity for sulphuric acid and unites with it, while 




How is fluoric acid obtained 1 
Explain this process. 



166 CHEMISTRY FOR BEGINNERS. 

the fluoric acid, being set free, escapes. The substance 
remaining in the flask is now a sulphate of lime, while 
that in the receiver is fluoric acid in the state of a gas. 

Properties of Fluoric Acid. 

One of the most important properties of fluoric acid is 
its great affinity for a mineral called silex, which con- 
stitutes the gritty part of stones, and forms a considerable 
portion of glass. This acid dissolves or eats glass, by 
uniting with the silex ; and this is the reason that glass 
vessels cannot be used for obtaining fluoric acid. 

In the figure is a rep- 
resentation of an etching 
box, placed over a fur- 
nace of coals; some fluor- 
spar being pounded, is put 
into the box, and sulphuric 
acid added. As soon as the 
gas begins to rise, a piece 
of glass, having been pre- 
viously coated over on one 
oirip with nepswax ann 
written upon or sketched 
through the wax with a pin, is placed over the box, with 
the waxed side down. To prevent the wax from melting 
by the heat, a sponge wet in cold water is applied to the 
upper side of the glass. In a few seconds after the gas 
has begun to act, the glass may be removed. On scrap- 
ing off the wax, the words written, or the picture sketch- 
ed, will be found engraven upon the glass. The wax is 
put on, in order to protect the glass from the action of the 
acid, except where the engraving is to appear. 



What are some of the most important properties of fluoric 
acid? 
Describe the process of etching or engraving on glass. 




BROMINE. 167 

The fluoric acid gas produces this effect on glass in 
consequence of acting upon a portion of the silex of 
which it is composed ; united to this silex, it forms a 
new compound, called silicated fluoric gas. 

The vapours of fluoric acid are very dangerous when 
brought to act upon any part of the body, and espe- 
cially when inhaled into the lungs. One writer on 
Chemistry mentions that his assistant suffered severely, 
for several weeks, in consequence of the vapour of this 
acid acting upon his finger ; and that six drops of the 
acid falling upon the back of a dog, in a spot where 
there was no hair, produced great agony and death in 
a few hours. 

Bromine. 

Bromine is a newly discovered element ; the name 
is from the Greek bromos, signifying an unpleasant 
odour, a circumstance which marks this substance. It 
was discovered by a French chemist in making some 
experiments with the ley obtained from the ashes of sea- 
weed and other marine plants. It exists in sea water in 
the state of a hydro bromic * acid united to magnesia. 
The process of collecting bromine, separate from its 
combinations, is long and difficult. 

It is a liquid of a deep red or brown colour, much 
heavier than water ; its weight in comparison to 
Hydrogen is 75. It is very volatile, that is, it has 
a tendency to pass into the state of a vapour ; a drop or 



* Hydro signifies in a moist state, or combined with hydrogen to 
form water. 



Why does fluoric acid produce the effect on glass which takes 
place in the process just described 1 

What is the effect of fluoric acid upon the animal system 1 

What does the name bromine signify, and when and how was 
the substance which is so called discovered 1 

What are its properties % 

14* 



168 CHEMISTRY FOR BEGINNERS. 

two will fill a quart glass vessel with red vapours. It 
is very poisonous ; its vapour supports combustion feebly 
but before at candle is extinguished in it, the flame, 
presents a singular appearance, being green at the bot- 
tom, and red at the top. Bromine does not change veg- 
etable blues to red, therefore it is not an acid ; but it 
bleaches them, and even destroys the colour of indigo. 

Its chemical affinities are numerous; it forms acids 
with hydrogen and oxygen ; it forms salts with alkalies 
which are called bromates, and combines with metals 
forming bromides. 

You will perceive that bromine in some respects re- 
sembles iodine, in connexion with which, it is usually 
found. Like iodine it is attracted to the positive pole of 
the galvanic batter}^ and is therefore classed among the 
electro-negative substances, oxygen, iodine, fluorine and 
one which we have not yet examined, called chlorine. 

Bromine is very rare and dear in this country. Two 
years ago, when Professor Silliman published the last 
volume of his 4 Elements of Chemistry,' he says, ' I 
have just obtained from Paris, two vials, containing each, 
not more than a thimble full ; the price was eight dol- 
lars.* 



Does it readily unite with other substances 7 
In what respects does bromine resemble iodine 1 
Is it a common substance ? 



MURIATIC ACID. 169 



CHAPTER XVI. 



Muriatic Acid. Chlorine. 

The last of the gases which we have to notice is called 
chlorine. We have deferred its examination, not be- 
cause it was an unimportant substance, but because 
there is some dispute among chemists as to its being an 
element, and we did not wish to perplex you with argu- 
ments about this, while you were ignorant of the na- 
ture of substances which are more easily understood. 

You have often been told, in the progress of your 
study, about muriatic acid ; now according to the pres- 
ent opinion of most chemists, respecting the nature of 
chlorine, and according to the principles by which acids 
are named, muriatic acid ought to be called hydro-chloric 
acid, it being considered as a compound consisting of 
hydrogen and chlorine, but the name having been long 
established, it is not easy to alter it, although for the sake 
of greater uniformity and clearness, many scientific men 
would be glad to do it. 

Muriatic Acid. 

Before proceeding to treat of chlorine directly, we will 
consider the substance from which it is obtained : this is 
muriatic acid, or, as before remarked, more scientifically 
(though not so commonly) called, hydro-chloric acid. 

Muriatic acid is so called from muria, the Latin name 
for sea salt, from which it is usually obtained. 

What gas is now to be considered? 

What does muriatic acid consist of, and what is the most proper 
name for it? 
From what substance is chlorine obtained 1 
Why is muriatic acid so named 1 



170 



CHEMISTRY FOR BEGINNERS. 



Liquid muriatic acid has long been known, but the 
discovery of its gas was not made till the latter part of 
the last century. 




The figure represents a method of obtaining muriatic 
acid gas — at A, is a retort containing common salt; 
sulphuric acid in sufficient quantity is poured through 
the glass tunnel, and the stop cock turned in order to 
prevent any gas escaping in that direction. B shows the 
tube of the retort passing under a receiver filled with 
mercury and inverted over a trough of mercury. At C 
is the chaffing dish of hot coals to hasten the process 
that is going on in the retort. 

Explanation. — Common salt is a muriate of soda ; 
that is, it is composed of muriatic acid united to soda ; 
the latter having a greater affinity for sulphuric acid, 
unites with it, forming sulphate of soda, and excludes 
the muriatic acid ; this rises in the retort, and is con- 
ducted through the tube into the receiver filled with 
mercury; as fast as the gas rises, the mercury gives 



Has it been lately discovered 1 

Describe the process for obtaining muriatic acid. 

How do you explain this process 1 



c 

uu 



MURIATIC ACID. 171 

place; as the receiver now appears, it is about half 
filled with gas. You will recollect that such is the af- 
finity of muriatic acid gas for water, that it cannot be 
collected through it like many of the other gases, as it 
unites with it and assumes the liquid state. 

Muriatic acid is heavier than the 
common air ; this is shown by col- 
lecting it, by means of an apparatus 
like that which is here represented. 
The bottle A, being filled with the sub- 
J$ stances which produce the gas, commu- 
nicates with an empty receiver B by 
the tube c, as the gas passes over, it set- 
tles at the bottom of the vessel, and the air consequently 
rises until the whole space being filled with the gas, it 
begins to issue forth from the mouth at d — it may be 
known by its peculiar smell and the white vapour which 
it forms. 

Properties of Muriatic Acid Gas. 

It is colourless, of a sharp odour and extinguishes 
combustion. Its affinity for water is such, that it attracts 
it from the atmosphere, and forms white vapours. It 
turns vegetable blue colours red. It melts ice with great 
rapidity, and is strongly absorbed by water. It is fatal 
to animal life. 

Liquid Muriatic Acid. 

Every chemical laboratory ought to be furnished with 
liquid muriatic acid, as it is of importance in many ex- 
periments. It is obtained by saturating water with 



What experiment proves muriatic acid gas to be heavier than 
common air ^ 
What are the properties of this gas 1 
How is liquid muriatic acid obtained % 



172 



CHEMISTRY FOR BEGINNERS. 



the gas, as in the figure. This is called Woulfe's ap- 
c c c 




paratus from the name of the inventor.* The retort 
a contains common salt and sulphuric acid; the muri- 
atic acid gas passes into the glass globe b, where it is 
washed from some sulphuric acid which is generally 
carried along with it — the gas then passes through the 
tube to the bottle next the globe, where it is received into 
water; when this water is saturated with the gas, it passes 
on through another tube to the next bottle, and thus the 
process is continued. — The number of bottles maybe in- 
creased or diminished. The strait tubes c, c, c, are called 
safety tubes ; they admit atmospheric air into each bottle 
when the gas ceases to come over from the retort, thus 
preventing a vacuum which might draw in the impure 
acid from the globe or first bottle. 

Silliman observes, ' the sulphuric, the nitric, and the 
muriatic, are the three cardinal acids of Chemistry and 
the arts. We could effect very little in practical Chem- 
istry without them. Of the three, the sulphuric is the 
most useful, because besides its own numerous and im- 
portant applications, it is the principal instrument in mak- 
ing the other two.' 

Uses of Muriatic Acid. 

Besides its many applications in assistingthe chemist in 
his analysis of other substances, muriatic acid is of impor- 

* For a further description of Woulfe's Apparatus, see the au- 
thor's Dictionary of Chemistry, articles ' Absorption,' and ' Ap- 
paratus.' 

"What does Silliman say of the importance of three of the acids? 



MURIATIC ACID. 173 

tant use in medicine and in the arts. It is very useful 
in a sick room, by destroying disagreeable odours, and 
preventing contagion. A little common salt in an 
earthen vessel, placed over coals, requires only the 
addition of a small quantity of sulphuric acid, in order 
to obtain the muriatic acid gas, the fumes of which are 
powerful to destroy the effect of other gases ; and 
all contagion is conveyed by means of bad air. or un- 
wholesome gases. An instance of the power of muri- 
atic acid gas as a disinfecting agent, is thus related by 
Professor Silliman. ' At Dijon, in France, there is a ca- 
thedral which in 1773, was from the corpses interred 
beneath it, so infected with putrid miasmata # that it had 
been deserted, after a number of unsuccessful attempts to 
remove them and purify the air by explosions, aromatics, 
&c. Application being made to Professor Morveauf 
for a remedy, he took a glass vessel, supported by one of 
cast iron, and placed it on a few live coals in the middle 
of the church. He then put into it six pounds of com- 
mon salt, and two pounds of sulphuric acid, and hastily 
withdrew closing the doors after him. The muriatic 
acid gas soon filled the vast space and could be perceived 
even at the doors. At the end of twelve hours, the 
church was thrown open and ventilated.' Thus by 
means of chemical science, that vast and ancient church 
which otherwise must have been destroyed or given up 
to owls and bats, lizards and noxious reptiles, was puri- 
fied and rendered a meet temple for the worship of God. 
Muriatic acid forms many combinations with other 
substances. With nitric acid it forms a compound called 
aqua regia, from the Latin, signifying kingly water. 

* Miasma is a Greek word, signifying noxious matter, or small 
particles which float in the air and produce diseases or bad smells. 
Miasmata is the plural of miasma. 

t A distinguished French chemist, see Dictionary of Chemistry, 
page 21. 

What are some of the uses of muriatic acid 1 



174 CHEMISTRY FOR BEGINNERS. 

This name was given by the first chemists who were 
called alchemists, and whose great object was to change 
all metals into gold. Nitro-m.uriatic acid, or aqua regia, 
is the only liquid known which has power to dissolve 
gold. With alkalies, muriatic acid forms salts, called 
muriates, as common salt, which is usually called the 
muriate of soda, &c. ; but which, according to late dis- 
coveries, is a chloride of sodium. — Muriatic acid is com- 
posed of 1 part chlorine, whose atom is called 36, united 
to 1 part hydrogen. 

The number, therefore, which represents this acid is 
37 ; this is called its chemical equivalent. You will re- 
member that hydrogen is the unit, or 1, to which all 
other elements are compared, and you will observe that 
one atom of chlorine weighs 36, while one atom of hy- 
drogen weighs only 1. 

Chlorine, or Oxmuriatic acid. 

Although this chapter is already a long one, we must 
ask your patience till we have examined chlorine, a 
description of which, although a simple substance as it is 
obtained from muriatic acid, we omitted till we had con- 
sidered the latter. It was in the year 1774, that Scheele, 
a Swedish chemist, being engaged in some experiments 
with the oxide of manganese, added to it liquid muriatic 
acid, when a gas, of a yellowish green colour, and a 
very strong and disagreeable smell, was observed to issue 
forth from the combination. Since that period, this gas 
and its compounds have been considered as among the 
most interesting subjects of study in the whole range of 
chemical science. 

It was at first thought, that, as the oxide of manganese 
contained a large portion of oxygen, a portion of the 

What are some of the combinations formed by the union of 
muriatic acid with other substances 7 

What is the chemical equivalent for muriatic acid 1 
When and by whom was chlorine discovered 7 



CHLORINE. 175 

latter, unitng to the muriatic acid gas, produced the newly- 
discovered gas, and on this supposition it was named 
ozmnriatic acid. 

As chemists attempted to decompose it, they found it 
resisted all the agents which they could employ for this 
purpose; they, therefore, began to believe that it was a 
simple substance, and gave it the new and independent 
name, Chlorine, from the Greek kloros, green, on ac- 
count of its peculiar colour. 

Method of obtaining Chlorine gas. 

Chlorine may be obtained with muriatic acid and the 

oxide of manganese, or 
by the following process, 
which is described in Silli- 
man's Chemistry : com- 
mon salt, oxide of mangan- 
ese, and sulphuric acid are 
put into a pot of sheet lead, 
such as you see in the fig- 
ure, and furnished with a 
leaden tube which is fitted 
into the cork. The pot is 
then placed in a tin pan 
containing hot water, and 
standing over a furnace. The gas must be collected in 
vessels filled wu'th warm water ; the water if cold will 
absorb the gas. 

Explanation. — How is chlorine obtained from the sub- 
stances w r hich were put together in the leaden vessel ? 
This question those will ask who desire to understand 



Why was this at first called oxy muriatic acid 1 

Why was its name afterwards changed to chlorine % 

How may chlorine be obtained 1 

Can you explain the rationale of the process by which chlorine 
is liberated from salt with the help of the oxide of manganese and 
sulphuric acid 1 

15 




176 CHEMISTRY FOR BEGINNERS. 

the causes of things ; we will therefore tell you what 
Chemists now believe to be the rationale * of this process. 

They think that chlorine combined with hydrogen, ex- 
ists in muriatic acid, forming hydro-chloric acid, which 
you will recollect we mentioned as being, now, the scien- 
tific name for muriatic acid. Now in order to obtain the 
chlorine, it is only necessary that the hydrogen shall be 
separated from the muriatic acid which the salt furnishes ; 
this is supposed to be done by means of the oxygen which 
comes from the oxide of manganese, and which impressed 
out by the union of the latter with the sulphuric acid, form- 
ing a sulphate of manganese. The oxygen furnished by 
the manganese, uniting to the hydrogen of the muriatic 
acid, forms water. One portion of the sulphuric acid 
unites with the soda of the common salt, (muriate of 
soda,) forming the sulphate of soda, while the muriatic 
acid being set free gives its hydrogen to tire oxygen of 
the manganese, and the new chlorine gas appears. 

Liquid chlorine may be obtained by putting pounded 
red lead, (oxide of lead) and common salt into a bottle 
containing water, to this mixture is added sulphuric acid ; 
after agitating the contents of the bottle, and plunging it 
into a cold water to promote the absorption of the gas by 
the water in the bottle, the liquid will assume that yel- 
lowish green colour peculiar to chlorine. Any piece of 
calico, or other coloured substance if introduced into this- 
bottle of liquid chlorine, will soon appear colourless. 

Properties of Chlorine Gas. 

The colour is greenish yellow ; the smell suffocating 
and offensive: it is very dangerous to the lungs, its e£ 

* Pronounced ra-shun-a-le, signifying the reasons for any pro- 
cess. This is a term so common in Chemistry that the author 
would not think of denning it, if this were not a work for ' Begin- 
Tiers. 1 



How may liquid chlorine be obtained 1 



CHLORINE. 177 

fects sometimes appearing long after the gas has been 
inhaled. * One of its most remarkable properties is that 
of destroying all animal and vegetable colours ; on this 
account, it is of great use in manufactories, where it is 
used in a combination with lime, called chloride of lime. 
Chlorine is a supporter of combustion, though far inferi- 
or to oxygen in this respect : a burning candle, held by 
a wire, in a vial of this gas burns a short time, though 
dimly, and with a reddish flame. Phosphorus and many 
other substances are inflamed spontaneously in chlorine 
gas ; on account of this property, the salts made with it, 
are used in the composition of fire crackers, rockets, and 
other fire works. 



* I cannot refrain from giving here a little notice of two young 
men, who have fallen victims to their zeal and boldness in the 
cause of science, especially, Chemistry; I allude to two sons' of 
Professor Amos Eaton, one of whom, Hezekiah, died recently at 
Lexington, Ky. filling with distinguished honour the station of 
assistant professor of Chemistry in Transylvania University. 
His brother Dwight, died at Troy, N. Y. several years before, too 
young to have made himself extensively known abroad. But 
those who witnessed the enthusiasm, and courage of these young 
men, for making the boldest experiments, the intuitive readiness 
with which they seized upon facts, and the clearness of their judg- 
ment, to make deductions from these, can never cease to lament 
that they should so often have exposed themselves to the dele- 
terious influences of deadly gases, which, operating upon their 
physical system like a slow poison, undermined their constitutions, 
and thus deprived their country of those who promised to take a 
high rank among the intellectual men of the age. To their 
father, the veteran whose life has been devoted to science, she 
owes the sacrifice of these two sons, the glory and pride of his 
declining years, while his own impaired health shows that he 
has not withheld the sacrifice of himself. 



What are the most important properties of chlorine gas 1 



178 



CHEMISTRY FOR BEGINNERS- 



The figure represents a tu- 
bulated bottle of chlorine gas 
into which some phosphorus 
being introduced, it burns 
spontaneously, and throws off 
brilliant jets of fire. A blad- 
der is fastened at the tubulure 
to give room for the ex- 
pansion of the chlorine gas 
by heat. The product of this 
combustion of phosphorus 
in chlorine, is called chloride 
of phosphorus. 

Many of the metals burn 
spontaneously in chlorine — 
The bell glass B, 
represents the com- 
bustion of gold leaf 
in this gas. The 
lower bell glass A, 
was first filled with 
chlorine over the 
pneumatic cistern ; 
the upper bell glass 
was exhausted of air 
by means of an air 
pump, and the pipe 
which is connected 
with the apparatus. 
On turning the stop- 
cock between the two 
bell glasses, the gas 
from the lower one 
rushed up to fill the 
vacuum, and the gold 
leaf was immediately inflamed, and burned with great 
brilliancy forming chloride of gold. 

How is the chloride of phosphorus formed % 

How is the process for burning gold leaf in chlorine described 1 




GENERAL REMARKS. 179 



CHAPTER XVII. 



We have now completed our view of the ponderable 
elements which are not metallic. You will reccollect that 
we first noticed the imponderables, caloric, light, electri- 
city, and magnetism, and then proceeded to the consider- 
ation of those elements which have definite weight, and 
are therefore called ponderable. 

The ponderable elements consist of two classes, sup- 
porters of combustion, and combustibles. 

The supporters of combustion are oxygen, chlorine, 
iodine, fluorine and bromine ; oxygen, by way of distinc- 
tion is called * the great supporter of combustion. 1 

The combustibles not metallic, are Hydrogen, Nitro- 
gen, * Sulphur, Phosphorus, Selenium, Carbon and 
Boron. 

We did not follow the arrangement above given of 
combustible and non-combustible substances in our view 
of these substances, because we wished first to examine 
Oxygen and Nitrogen to show the constituents of the at- 
mosphere, and then we examined Hydrogen in order 
that we might illustrate the composition of water. Chlo- 

* Nitrogen is combustible in the sense in which Chemists con- 
sider combustion to be the union of a substance with oxygen ; but 
it does not take fire on being brought in contact with a burning 
substance, and is not therefore 'combustible in the common under- 
standing of the term. 



What elements have we now in this work considered 7 
Of what two classes do the ponderable elements consist 1 
Which are supporters of combustion ? 
Which are non-metallic combustibles? 

Why were not these classes observed in the previous arrange- 
ments of the subjects of this -work 7 

15* 



180 CHEMISTRY FOR BEGINNERS. 

rine was considered last, because the process for obtain- 
ing- it, is somewhat complicated and might embarrass a 
pupil in the commencement of his studies. 

With that part of the alphabet of Chemistry which 
we have examined, are formed either amongst themselves, 
or in connection with other substances, all of the most 
important combinations in nature. We shall now con- 
sider some of these combinations of non-metallic sub- 
stances with each other, which we have hitherto omitted, 
that your attention might be chiefly given to the elements 
themselves. 

AMMONIA. 

A compound of Nitrogen and Hydrogen. 

Ammonia* consists of one part Nitrogen, which is rep- 
resented by the number 14, and of three parts Hydrogen 
which are called 3 ; therefore as 14 and 3 are 17, the 
latter number represents Ammonia, or is called its chem- 
ical equivalent. 

Hartshorn (sometimes called volatile salts, and volatile 
spirits) is an article in very common use. In powder it 
is used in smelling bottles, and in a liquid state it is used 
for medicine. Hartshorn is so called because it is ob- 
tained by burning the horns of harts or deer. Hartshorn 
is a carbonate of ammonia. 

* The name ammonia, is by some, supposed to be derived from 
amnos, sand, because^it was first procured from the sandy country 
Lybia, by others it is thought to be named from the temple of Ju- 
piter ammon. 



What is said of the importance of the elements which have 
been examined ? 

What does ammonia consist of, and by what number is it rep- 
resented ? 

What is hartshorn, how obtained, and how used % 



AMMONIA. 



181 




By applying heat to the liquid ammonia, 
a gas of a very powerful nature is disen- 
gaged; a, is the vessel containing the 
liquid ammonia, b, the lamp, c, the receiver, 
and d, the tube which connects the receiver 
to the flask. The gas of ammonia, being 
lighter than the air, rises, and takes its place 
in the upper vessel. 

The following figure represents another 
mode of obtaining this gas; the receiver being 
filled with mercury and inverted over a mer- 
curial cistern. The retort, instead of liquid 
ammonia, contains pow- 
dered muriate of ammonia, 
and slacked quick lime. 
The muriatic acid leaves 
the ammonia to unite with 
the lime, and the ammonia 
is set free. This experi- 
ment shows the action of 
two solids in producing 
elective affinity. 



Muriate of ammonia is known in the shops of drug- 
gists as sal-ammoniac, which means salt of ammonia. 

Ammonia cannot be produced by synthesis or mixing 
hydrogen and nitrogen gases ; but it seems necessary 
that they should be brought in contact, at the instant 
they pass from other combinations, in order to unite in 
the proportions necessary to form this substance. 




How may the gas called ammonia be obtained from liquid am- 
monia % 

How may it be obtained from muriate of ammonia and lime 1 

What is the common name of muriate of ammonia'? 

Can ammonia be produced by a mixture of the gases which 
compose it 7 



182 



CHEMISTRY FOR BEGINNERS. 



During the decomposition of animal substances both 
hydrogen and nitrogen are given off, these unite, and 
form ammonia ; thus from putrid and offensive matter 
arises a gas the smell of which is reviving, and a pre- 
ventive to putrefaction. 

The figure shows a 
method of obtaining liq- 
uid ammonia. The retort 
contains the muriate of 
ammonia and lime ; the 
tube conducts the gas 
into a bottle containing 
cold water, which ab- 
sorbs it rapidly. 

Ammonia is an alkali; 
— that is, it changes veg- 
etable red colours, blue; 
changes blue colours 
green, and yellow col- 
ours brown ; it is caustic 
to the taste ; it combines 
with acids to form salts, and with oils to form soaps. 

The volatile liniment, used for burns and sore throats, 
is composed of ammonia and sweet oil. 

Combinations of carbon with simple bodies are called 
carburets ; — the most important of these is carburetted 
hydrogen, one kind of which forms the gas which is 
used for lighting the streets of cities. 

Those of you who have walked out of an evening in 
the principal streets of New York, or of some other large 
city, cannot fail to have noticed the beautiful and brilliant 
lights which illuminate the streets, shops, and public 




What gas is produced during the decomposition of animal sub- 
stances 1 

How is liquid ammonia produced ? 

Why is ammonia considered as an alkali 1 

With what does it combine to form volatile liniment ? 



GAS LIGHTS. 183 

places ; sometimes issuing forth in many small jets of 
flame from elegant chandeliers of curious construction, 
and at others appearing in one large effulgent blaze. 
These lights burn without any wick ; they are caused 
by the combustion of gas. You will recollect that car- 
bon and hydrogen are both highly combustible substan- 
ces ; we should naturally infer that when united, they 
would burn with force and brilliancy. 

There are several varieties of carburetted hydrogen; 
that which is used for gas lights is either obtained from 
coal or oil. Coal, we have found, is chiefly composed of 
carbon ; that which is used for gas lights is a damp 
kind, called pit coal, which is dug from mines. The 
water in the coal furnishes the hydrogen. Oil is com- 
posed principally of carbon and hydrogen ; the gas 
obtained from it is much purer than the coal gas. 

Coal Gas. 

An apparatus for furnishing coal gas lights consists 
of a large iron vessel which contains the coal ; this ves- 
sel is placed over a furnace, and the gas which rises is 
made to pass through a tube into a vessel of cold water, 
called a condenser, which cleanses it of many impurities ; 
it is then conducted through a mixture of quick lime and 
water, called the purifier, which absorbs the carbonic 
acid and sulphuretted hydrogen ; it is then transmitted 
into a gasometer, or vessel prepared for the reception of 
the gas, and furnished with tubes which may be made 
to pass in any direction which is required. In some 
large gas manufactories, the gasometers are twenty feet 
high and thirty in diameter. They are made of sheet 



What are carburets 1 

What lights are used in some cities for lighting the streets, 
shops, &c. 1 

From what substances is the carburetted hydrogen used for gas 
lights commonly obtained 1 

How is coal gas manufacftired and conveyed to different places 1 



184 



CHEMISTRY FOR BEGINNERS. 



iron — from this great fountain of gas, tubes placed under 
ground proceed to the different streets, and buildings 
where it is used, in the same manner as water is con- 
ducted from one place to another through hollow cylin- 
ders placed under ground. 

Oil Gas. 

^ Oil gas is obtained chiefly by the distillation of whale 
oil, which is made to drop slowly into a vessel containing 
pieces of red hot bricks or coal ; the apparatus in other 
respects resembles that for obtaining coal gas. The oil 
gas is considered the most pure, and brilliant; it is the 
cheapest, except in places very near to coal mines, 
where the coal is sold very cheap. 

The vessel a is supposed to be 
made of cast iron ; in its cover are 
two openings, one of which has fitted 
to it a small copper tube having a 
funnel shaped vessel b, to receive the 
oil ; to the other opening is fitted a 
bent iron tube c which communicates 
with a copper condensing vessel d ; 
from the top of this issues a lead 
pipe which may be made to commu- 
nicate with a gas holder. In order 
to obtain oil gas, pieces of brick are 
put into the vessel a which is placed 
over a furnace to be heated ; when 
it is heated to redness, oil is poured into the funnel 
shaped vessel and the stop cock at / being turned it 
falls drop by drop upon the bricks ; the gas which is 
produced passes into the condenser d. 

Spirits of turpentine and common resin may be used 
in the manufacture of gas lights. If you have ever no- 




What is said of oil gas, and the mode of obtaining it 1 
Describe the apparatus illustrating the manufacture of oil gas. 
What other substances besides coal and oil may be used for gas 
lights 7 



GAS LIGHTS. 



185 



ticed the brilliant light made by the burning of a pine 
knot, you can readily believe that turpentine, which is 
the substance that burns so brightly, might afford a gas 
that would be very luminous. 

The figure shows a portable 
gas light, or a copper vessel, 
which being rilled with olerl- 
ant gas can be conveyed from 
one place to another. The 
flexible pipe serves the purpose 
of conveying the gas into the 
receiver, after it has been ex- 
hausted of air; the stop cock 
near the insertion of the pipe 
is then turned to prevent the 
escape of the gas, and the one 
near the perpendicular tube is 
turned to admit the gas through 
the orifice, where after being 
inflamed, it continues to burn 
till the whole is consumed. 




Bi-Carburetted Hydrogen, or Olefiant Gas. 

The gas used for lights is bi *-carburetted hydrogen ; 
that is, 2 atoms of carbon united to 2 atoms of hydrogen 
— carbon being represented by 6, we have 12 of carbon 
to 2 hydrogen (an atom of hydrogen being 1 ) ; so that 
14 is the equivalent of this gas. 

* From the Greek bis, two, meaning twice carburetted hydrogen. 



What are the proportions of carbon and hydrogen in bi-carbu- 
retted hydrogen, and why is it so called % 



186 CHEMISTRY FOR BEGINNERS. 

Bi-carburetted hydrogen is called olefiant gas, because 
with chlorine it forms an oily substance ; it is also called 
heavy carburetted hydrogen, on account of its specific 
gravity being greater than that of the other combinations 
of carbon and hydrogen. 

The bi-carburetted hydrogen or olefiant gas gives the 
most luminous flame of all gases — hydrogen burns with 
a pale light, simple carburetted hydrogen which con- 
tains but one atom of carbon burns more vividly, but the 
additional atom of carbon which exists in the olefiant 
gas renders it still more brilliant. 

This gas is obtained for experiments, by heating in a 
retort, alcohol with sulphuric acid ; the alcohol burns, 
and the carbon and hydrogen of which it is composed, 
unite and form the olefiant gas, which is collected over 
water. If a small quantity of pounded coal be put into 
the bowl of a tobacco pipe, covered over the top with 
clay and then placed in burning coals, a stream of olefiant 
gas will issue forth, which may be known by applying 
to it a lighted taper, when it will be inflamed. 

Light Carburetted Hydrogen. 

We have here but 1 atom of carbon to 2 of hydrogen ; 
therefore, as 6 the atom of the one, to 2 the two atoms of 
the other, make 8, this number is the representative of 
carburetted hydrogen — the difference between this gas 
and the bi-carburetted hydrogen, consists then, in the 
different proportion of carbon which exists in them. 

The specific gravity of this gas is less than that of the 
bi-carburet, on account of its containing less carbon. 



Why is it also called olefiant gas % 

Which is the most luminous of the gases, and why is it so 7 
How may olefiant gas be obtained for experiments ? 
What are the proportions of hydrogen and carbon in light car- 
buretted hydrogen'? 
Why is its specific gravity less than that of the bi-carburet 1 



CARBURETTED HYDROGEN. 187 

Carburet led Hydrogen. 

It is called inflammable air, and sometimes the in- 
flammable air of marshes, because it is formed in low, 
damp grounds, during the decomposition of animal sub- 
stances. It may be collected over muddy and stagnant 
waters, by stirring the mud beneath a receiver ; as ap- 



pears in the cut, which represents a vessel suspended 
in the water of a pond, and the gas rising as the mud 
at the bottom is disturbed. 

Coal mines, which furnish in abundance, the elements 
of carburetted hydrogen, are often scenes of fatal acci- 
dents to the workmen engaged in them. Ascending 
from the coal beds, the gas remains floating in the air, and 
the instant it comes in contact with a flame, takes fire and 
explodes with great violence. 

In England there are many coal mines ; whole vil- 
lages of people attend to the mining business as their 
only way of getting a support; some families live 

Why is it sometimes called the inflammable air of marshes ! 
In what way does this gas cause accidents in coal mines 'I 
Why did this gas become a terror to the miners of England 1 
16 



188 CHEMISTRY FOR BEGINNERS. 

wholly in the mines; and it is said people are often born 
in them, and live to old age without ever leaving them. 
It was a dreadful thing to these poor people to feel in 
constant dread of the wild-fire damp, as they called this 
gas — for they cannot work without a light, and their 
lamp must every moment expose them to this destruc- 
tion. 

Many dreadful accidents having occurred, in some in- 
stances destroying nearly a hundred workmen at a time. 
Sir Humphrey Davy, who was known as a man of much 
science, was applied to, with the hope that he might dis- 
cover some means by which the miner could pursue his 
employment, and thus furnish the country with fuel, 
without the danger of such dreadful accidents. Sir 
Humphrey listened to the application with deep interest ; 
he immediately took a journey to the coal region; he 
went into the mines, conversed with the miners, and ob- 
tained from them all the information they could give, 
respecting the nature of this fire damp. He then col- 
lected the gas, and examined its properties by various 
experiments. 

He discovered one fact with regard to this substance, 
which suggested to him a way of preventing its explo- 
sion. He found that even red hot iron, in contact with 
the gas, did not set it on fire, while the smallest point of 
flame would cause an immediate explosion ; this brought 
to his mind the fact that another chemist, Dr. Wollaston, 
had discovered, ' that an explosive mixture cannot be kin- 
dled in a glass tube so narrow as one seventh of an inch 



What is said of the application made to Sir* Humphrey Davy, 
and of his attention to it ? 
What suggested to him the idea of his safety lamp? 



SAFETY LAMP. 



189 



in diameter.' This fact he proved by the experiment rep- 
resented in the figure. He procured two vessels of the 




light carburetted hydrogen gas, or fire-damp, each fitted 
with a tube and stop-cock, and as the gas issued forth at 
each orifice he set fire to it ; when it was burning he held 
over one orifice a, a piece of fine wire gauze or net-work; 
but, as you see in the figure, the blaze, instead of pass- 
ing through it, was turned away. He set fire to the gas 
of the other orifice b, above the wire gauze, and although 
it burnt freely, the flame had no effect upon the gas be- 
low. The network of wire is made of a vast num- 
ber of very small tubes connected together. Sir Hum- 
phrey Davy having proved that such a net-work would 
secure the flame from the external air, then went to work 
and constructed a lamp, which is known throughout the 
civilized world as Davy's Safety 'Lamp. 



190 



CHEMISTRY FOR BEGINNERS. 




This is the safety lamp 
which you see in the figure. 
The oil and wick are in the 
lower part, which is fed with 
oil by the spout on the side. 
The flame is surrounded by 
a cylinder or cage of wire 
gauze, so fine that in every 
square inch there are at least, 
625 apertures. At the top, 
where the greatest heat exists 
the wire gauze is double. 
There are conveniences for 
raising the wick, and re- 
plenishing the oil, without 
opening the lamp and thus 
exposing the flame to the ex- 
ternal air. 

This figure represents a large 
bell glass A, suspended over a 
jar C, filled with carburetted 
hydrogen, and standing over 
w r ater of the pneumatic cistern 
D D. A safety lamp B is held 
under the bell glass ; now by 
turning a stop-cock, fitted to the 
tube of the jar C which contains 
the gas, the inflammable air is 
allowed to pass up into the bell 
glass A and mingle with the 
common air which it contains ; a 
certain portion of which renders 
the fire-damp more explosive 
than when unmixed. The 
flame of the lamp will change 
its appearance and exhibit a 
green or delicate blue colour, 



Describe the safety lamp. 

What experiment proves perfectly that the safety lamp is se- 
cure even when burning in an atmosphere of inflammable air 1 



SULPHURETTED HYDROGEN. 191 

and finally be extinguished; bat it will not set fire to the 
external gas, which would be the case, should the small- 
est portion of flame come in contact with it. 

From the little sketch we have given of the method 
pursued by Sir Humphrey Davy in his invention of the 
safety lamp, the young may see that knowledge does not, 
of itself, come into the mind, without labour. When a 
person begins to search into the nature of things, then it 
is that new ideas seem to arise in the mind — one experi- 
ment suggests another, and so on until the process often 
ends in the discovery of some new principle, or some 
new application of principles before known. In this way 
oxygen gas, and all the other gases, so important in 
chemical science, were discovered ; and to such a process 
of inquiry we owe, not only the invention of the safety 
lamp, which gives security to thousands of labourers, as 
they go forth to their daily toil, but that of the steam 
engine, the printing press, and a vast number of im- 
provements which tend to the comfort of life and promote 
the good of society. 



CHAPTER XVIII. 



Sulphuretted Hydrogen* Cyanogen, Prussic Acid. 

SULPHURETTED HYDROGEN. 

Compound of Sulphur and Hydrogen. 

By an union of one atom of sulphur represented by 
the number 16, and one atom of hydrogen, represented 

In what way have most important discoveries among men been 
made 1 What is sulphuretted hydrogen'? 
16* 



192 CHEMISTRY FOR BEGINNERS. 

by i, a gas is produced called Sulphuretted Hydrogen, 
of which the chemical equivalent is 1 7 ; or, this is the 
sum of the two elements when added together. 

The termination uret is applied to combinations of 
simple combustible, non-metallic substances with each 
other, and with the metals, alkalies, and earths ; thus we 
have sulphuret of phosphorus, sulphuret of iron, phos- 
phoret of lime, &c. But when the compound is gaseous, 
this is signified by the termination uretted, as we have 
just seen in the combinations of carbon and hydrogen, 
called carburetted hydrogen. 

Modes of obtaining Sulphuretted Hydrogen. 

Sulphuretted hydrogen is obtained 
by heating sulphur in connexion with 
hydrogen gas, as represented in the 
figure; the sulphur or brimstone is 
contained in the lower vessel, and the 
upper one is filled with hydrogen gas, 
which, from its specific levity keeps 
its place ; as heat is applied, the sul- 
phur or becomes a vapour, rises and 
unites with the hydrogen ; thus form- 
ing sulphuretted hydrogen. 

The same gas may also be obtained 
by heating sulphuric acid and the sul- 
phuret of iron, (a combination of sul- 
phur and iron). This is an instance of double elective 
affinity ; the oxygen of the water of the liquid sulphu- 
ric acid, unites to the iron of the sulphuret, and sets the 
sulphur free ; while the hydrogen of the water, being 
at liberty, unites with the sulphur, and forms sulphuret- 
ted hydrogen. 

How are the terminations uret and uretted applied 1 
How is sulphuretted hydrogen obtained'? 
By what process is sulphuretted hydrogen obtained from sul- 
phuric acid and the sulphuret of iron 1 




SULPHURETTED HYDROGEN. 193 

This is one of the most offensive of all the gases ; it 
is not only highly disagreeable in its odour, which re- 
sembles that of bad eggs, but is very destructive to 
animal life ; when pure, it kills almost instantly ; and is 
very noxious, even when mingled with a large proportion 
of common air. 

This gas is formed in nature in various places, partic- 
ularly in cities, about wharves and in sinks where filth 
is suffered to accumulate. It exists in the atmosphere 
around sulphurous springs. 

One property of this gas renders it of much impor- 
tance to the world, viz ; its power as a test to show the 
existence of poisonous substances— many of the most 
active poisons have a metallic basis — sulphuretted hy- 
drogen has such an affinity for metals that it unites with 
them, and, by a change of colour, indicates their exist- 
ence, where it otherwise might not be suspected. Thus 
arsenic, one of the most deadly poisons, may be detected 
by a yellow precipitate, and mercury by a black precipi- 
tate with sulphuretted hydrogen. 

White lead (carbonate of lead) becomes black when 
exposed to sulphuretted hydrogen gas ; and bismuth, 
another metal, becomes a dark brown — both these sub- 
stances are used as the basis of the paints or cosmetics, 
which in some countries are used by females, under the 
mistaken idea of improving their complexions ; bismuth 
is manufactured into a brilliant, white powder, sold under 
the name of pearl-powder. It would be a very unpleas- 
ant circumstance to a beautiful, painted lady, walking 
near a sulphur spring, or other place where the atmos- 
phere contained some portion of sulphuretted hydrogen, 
to have her colour suddenly changed to that of a tawny 



What are some of its properties 1 
Does it exist in nature 1 

What important property does this gas possess? 
To what accident are persons exposed who use such cosmetics 
as pearl-powder ; white paint, &c. ? 



194 CHEMISTRY FOR BEGINNERS. 

mulatto; but this is a risk that must always be incurred 
by those who use cosmetics prepared from mineral sub- 
stances. 

You have probably observed that a silver spoon, af- 
ter being put into a boiled egg, becomes blackened — 
this is the effect of sulphuretted hydrogen — the yolk 
of eggs contains sulphur, the watery part contain hydro- 
gen ; when heated in cooking the two elements unite. 

There is a combination called bi-sulphuretted hydro- 
gen, in which two atoms of sulphur unite to one of hy- 
drogen. 

CYANOGEN. 

Compound of Nitrogen and Carbon. 

The word cyanogen is derived from the Greek hianos 
blue, and gennao to produce, signifying the producer of 
blue. This substance gives its colour to the paint called 
prussian blue. 

Prussian blue was discovered at Berlin, in Prussia, in 
the year 1704, and was then supposed to consist of an 
acid called prussic acid, united to iron; — by chemists 
prussian blue was for more than a hundred years con- 
sidered as a prussiate of iron. The discovery of cyano- 
gen, by one of the French chemists, a few years since, 
has wholly altered the names of the substances with 
which it combines. 

It is obtained from a substance now called the cyanuret 
or cyanide of mercury, (formerly prussiate of mercury,) 
which on being heated in a small glass retort, gives off 
the cyanogen gas. 

This is found to consist of 2 parts of carbon 12, and 1 
part of nitrogen 14 — thus the representative number of 

Why does a silver spoon become blackened in boiled eggs'? 
What is bi-siilphuretted hydrogen ? 
Why is cyanogen thus named 1 

What was prussian blue when first discovered supposed to con- 
sist of? 
How is cyanogen obtained 1 



COMBINATION OF HYDRON AND CANOGEN. 195 

cyanogen is 26. Cyanogen, therefore, is not a simple 
element, though it forms combinations with other sub- 
stances, much in the same manner as our chemical al- 
phabet, oxygen, nitrogen, &c. 

It combines with oxygen to form cyanic and cyanous 
acids, and another acid called fulminic* 

Prussic acid — hydro-cyanic acid. 

The acid which was obtained from prussian blue w r as 
at first called prussic acid ; — as it is now known to be a 
combination of hydrogen and cyanogen, its more scien- 
tific name is hydro-cyanic acid. 

This is an extremely poisonous substance ; it kills 
small animals instantly — a single drop of it falling upon 
the arm of a German chemist, is said to have destroyed 
his life. Silliman relates that a medicinal preparation 
of this acid, which he had received from Paris, happen- 
ing to get spilled upon the floor, although it was imme- 
diately covered and* removed, produced alarming effects 
upon those present, such as fainting, loss of pulse, &c. 
w r hich continued for several days. 

Prussic acid exists in some vegetables, as the leaves 
and blossoms of the peach, and the kernels of the fruit, 
of the laurel and almond. 

It is used in medicine but much diluted. So powerful 
an agent as this, should never be used at all but by a 
person of great science and experience. 



* From fulminate to thunder ; this acid forms explosive mixtures 
when combined with some of the metals. 



Is cyanogen a simple substance 1 

Does cyanogen combine with oxygen T 

What is the scientific name for prussic acid 1 

What are the properties of this acid 1 

Does it exist in nature *? 

What is said of its use in medicine 1 



196 CHEMISTRY FOR BEGINNERS. 

Prussicacid, combined with iron, forms prussian blue, 
which is scientifically called hydro-ferro cyanate of iron* 

Prussic acid is remarkable for its tendency to decom- 
position, as its elements seem so feebly united that they 
separate spontaneously. These elements, you will recol- 
lect, are three, nitrogen, carbon, and hydrogen. 

No oxygen exists in this acid. It has neither an acid 
taste, nor does it turn blue vegetables red; but it is 
called an acid, because it combines with alkalies to form 
salts, which are termed hydro-cyanates or prussiates. 

Cyanogen, you will recollect, is represented in Chem- 
istry by the number 26, — one part of hydrogen, whose 
atom is 1 being, added, gives 27 as the representative 
number of hydro-cyanic or prussic acid. 

Cyanogen is a substance about which much might be 
said, but in a Chemistry for Beginners it is not to be ex- 
pected that the different subjects named will be thoroughly 
investigated. It is the object of this book to give young 
persons a taste for the science, so that they can under- 
stand more extensive works, and especially to direct their 
attention towards the Great Volume of Mature of which 
God is the Author. 

We find in pursuing our researches in Chemistry, 
how He has distributed around us the most deadly ele- 
ments, as if to show that while He holds in his hand 
powers that would instantly destroy us, He has been 

* Hydro from hydrogen, ferro from the Latin ferrim, iron. 
For a particular account of the discovery of prussian blue, and 
the manner of obtaining it, see Dictionary of Chemistry, p. 122. 

What is the scientific name of prussian blue 1 

What are the elements which form prussic acid, and are they 

easily separated 7 

Why is this substance called an acid 1 

What is the representative number of prussic acid^ 

What remark is made respecting the object of this book *? 

What do we find in pursuing our chemical researches with 

respect to the creations of God] 



ALKALINE METALS. 197 

pleased so to arrange and temper them, as to render 
them harmless or conducive to our service and comfort. 
We have, in the progress of our work, concluded our 
examination of the imponderable elements, of all the non- 
metallic, ponderable elements ; we shall, in our next 
chapter, commence with a new class of simple substan- 
ces. 



CHAPTER XIX 



Metalloids. Alkaline Metals. 

alkaline metals, — Potassium, Sodium, Calcium, tyc. 

We shall now, for a time, be occupied with a class of 
elements called metalloids ; the termination oids is from 
the Greek, and signifies like or similar to. The word 
metalloids means, similar to metals. 

The metalloids are in the strictest sense of the word 
metals ; but they differ from the proper metals in their 
great affinity for oxygen, which circumstance renders it 
difficult either to obtain or preserve them in a state of 
purity; they differ greatly from the metals in their spe- 
cific gravity. It is but recently, that they have been 
known to exist ; the substances from which they are ob- 
tained, having been considered as simple, until late dis- 
coveries have proved them to be compound. 



What subjects have now been considered 1 

What is understood by the term metalloids 1 

How do the metalloids differ from the proper metals 1 



198 CHEMISTRY FOR BEGINNERS. 

Potash, soda, and lime were formerly classed as pure 
alkalies, but they are now known to be oxides of metals. 

POTASH. 

Combination of Potassium and Oxygen. 

The potash of commerce is obtained by evaporating 
the ley of wood ashes and that of other vegetables. It 
was formerly called vegetable alkali. The name potash 
was given becausb the ley was boiled down in pots. 

Potash was known to the ancients. The Romans in 
the days of Julius Csesar, are said to have used soap 
made of ashes and tallow ; and at Pompeii, which was 
buried by the eruption of Mount Vesuvius, 79 years after 
Christ, a soap-boiler's shop has been discovered, which 
contained soap that appeared to be of the same nature as 
our common soap, and which, although it must have been 
made more than seventeen hundred years, was perfectly 
preserved. 

The ley that is obtained from the common wood ashes, 
and used in families for making soap, is a very impure 
solution of potash ; as it usually contains more or less 
carbonic acid, quick lime is thrown into it, to which the 
acid unites, forming a carbonate of lime, and leaving 
the potash to act upon the grease. 

Potash, in its purest state, is not an element, but an 
oxide of a metal called potassium. 

Sir Humphrey Davy, in 1807, discovered the com- 
pound nature of potash. He subjected this alkali to the 
action of a powerful galvanic battery ; it melted, oxygen 
appeared at the positive pole, and some metallic globules 
at the negative pole. 

What are potash, soda, and lime 1 
How is potash obtained, and why is it so called 1 
Has it been long known and used 1 
Why is lime used in making soap 1 
Is potash an element or a compound % 

How did Sir Humphrey Davy discover the compound nature 
of potash ? 



POTASH. 



199 




The figure repre- 
sents a galvanic bat- 
tery ; A is the wooden 
trough, having parti- 
tions, the spaces be- 
tween which are filled 
with weak brine or 
with water, containing 
a small portion of sul- 
phuric or some other 
acid. The plates B 
which are alternately 
of zinc and copper, be- 
ing shut down into the 
cells the galvanic action commences, or the opposite 
electricities are disengaged. Z represents the zinc or 
positive pole, being connected with a zinc plate ; and 
C the copper or negative pole, being connected with a 
copper plate. The substance to be acted upon is placed 
in contact with the two poles ; — if it is a compound body 
its elements will go to the different poles. As in the 
oxide of a metal, the oxygen will always go to the pos- 
itive pole, and the metal to the negative. We will now 
suppose Sir Humphrey Davy attempting to learn the 
nature of potash — he brings a piece of dry, solid potash, 
places it upon a plate of platina within the galvanic cir- 
cle (see P) — the potash begins to melt, and soon vanishes 
while oxygen appears at the positive pole Z, and little me- 
tallic drops at the negative pole C. When he saw this, 
the philosopher knew that he had made a grand discov- 
ery, which would greatly change the science of Chem- 
istry, and be followed by many other discoveries. 

This indeed was the case, for as soon as other chem- 
ists knew of Davy's discovery, they began to make new 



Describe the figure and the manner in which the decomposition 
of potash may be effected. 
What effect had Davy's discovery upon the science 1 

17 



200 CHEMISTRY FOR BEGINNERS. 

experiments ; and it was but a short time before several 
alkalies, hitherto considered as elements, were proved 
to be compounds, among these were soda and lime. 

Potassium has such an affinity for oxygen, that in the 
air or in water, it combines with it ; for this reason, it is 
preserved by chemists, in an oily substance, called naptha. 
It is on account of this affinity for oxygen, that potassi- 
um is found highly useful in decomposing other sub- 
stances, by combining with their oxygen. 

The union of potassium with oxygen, forms potash ; 
thus the compound nature of this substance is proved by 
synthesis as well as analysis. 

Potash is an oxide of potassium. Pearlash is a car- 
bonate of potash. Saltpetre is a nitrate of potash. 

Pure potash dissolved in water is a hydrate of potash. 

Potassium does not exist in nature, except in a state 
of combination ; this you will at once perceive must be 
the case, as it takes oxygen from both air and water, 
and becomes potash. 

Potash is a powerful alkali, and therefore has a strong 
tendency to unite with acids ; the effect of this union is 
a neutral salt, which exhibits neither acid nor alkaline 
properties. If the colour of a carpet, or a garment is 
changed by an acid, a solution of potash, by neutralizing 
the acid, would remove the stain. Pearlash is better 
for this purpose, as pure potash is very caustic, and 
has such an affinity for animal substances as to destroy 
them. Woollen cloths are made of an animal sub- 
stance. 

Besides its use in making soap, potash is employed 



Why cannot potassium be preserved in water or in the open air 1 

What substance is formed by the union of potassium with oxy- 
gen 1 

What'are the chemical terms for potash, pearlash, and salt petre ? 

What is a hydrate of potash 1 

Does potassium exist pure in nature 1 

What is the effect of the union of potash with acids, and how 
may a knowledge of this effect be turned to an economical purpose'? 



SODA. 201 

in the manufacture of glass, by melting it with sand ; 
under the form of pearlash, it is much used by the 
housekeeper to make gingerbread and other cakes light ; 
it is often called sal-ceratus. 

Potassium is soft like wax, and has a beautiful metal- 
lic lustre, but it is immediately covered with a coat- of 
potash, if exposed to the air ; if thrown upon water it 
floats and burns on its surface, so rapidly does it unite 
with oxygen. 

The specific gravity of potash is 1.700, that of potas- 
sium 0.805, or less than water. 

The weight of potassium compared with hydrogen is 
40 ; potash consists of 1 atom of potassium and 1 of 
oxygen, 8 ; it is, therefore, represented by 48. 

SODA. 

Compound of Sodium and Oxygen. 

You will readily comprehend, from what has been 
said respecting the nature of potash, that soda, another 
powerful alkali, is also a compound substance. This is 
the oxide of sodium. 

The soda in common use is not, however, the pure 
oxide of sodium, but a carbonate of soda. It was former- 
ly called barilla. 

By an Arabian chemist of the ninth century, soda was 
described, but considered as the same thing with potash. 
The difference between them is in many respects great. 
Soda is obtained by the burning of salt-water plants ; 
the ashes are leached and the ley is then evaporated. 

What are some of the uses to which potash is applied 7 ? 

What are some of the properties of potassium 1 

What is the specific gravity of both potash and potassium 1 

What is the weight of an atom of potassium and the represen- 
tative number of potash? 

What is soda 3 

What is the soda in common use 1 

How do soda and potash differ, and in what respects are the) r 
similar ? 



202 CHEMISTRY FOR BEGINNERS. 

The attraction of soda for acids is less than that of pot- 
ash ; the salts of soda are decomposed by potash, which 
aUracts from them their acids. Soda forms with oil 
hard soap; potash with oil, forms soft soap. Soda is used 
in the manufacture of glass, and is for this purpose pre- 
ferred to potash. Both the carbonate of soda and that 
of potash are used in weak solutions, to correct acidity 
of the stomach. Potash is found in the mineral king- 
dom; as in felspar, one of the constituents of some of 
the primitive rocks, it composes 10 parts in 100. Soda 
is the basis of common salt, and therefore extensively 
diffused throughout the mineral kingdom in beds, and 
even mountains of salt, and in the waters of the ocean, 
and salt lakes and springs. 

Common salt is a muriate of soda, or according to the 
present state of chemical science, a chloride of sodium. 
Glauber's salts is a sulphate of soda. 

Sodium, the element which forms the basis of soda, is 
obtained by means of galvanic decomposition, it may 
also be obtained by being heated in a gun-barrel with 
iron filings, which take up the oxygen, and the melted 
sodium flows down in a liquid state. Potassium may 
also be obtained by this latter mode, which was first 
practised by two distinguished French chemists, Gay- 
Lussac and Thenard. In many of its properties, sodium 
resembles potassium. 

The weight of sodium compared with hydrogen is 
24 ; combined with 1 atom of oxygen, 8, it forms the 
oxide of sodium or soda, represented by 32. 

LIME. 

Combination of Calcium and Oxygen. 

Lime was known to the ancients ; probably not so 
early as the attempt to build the tower of Babel, for it is 

What are the chemical names of common salt and Glauber's salts'? 
How is sodium obtained, and what metal does it resemble 1 
What is the weight of sodium and soda 1 
Was lime known to the ancients'? 



LIME. 203 

said in Scripture, that they had bricks for stone, and 
slime for mortar. This slime was a substance dug from 
pits in the earth, about India and some other parts of 
Asia ; it contained an oily, adhesive substance, called 
bitumen, the same with which Noah coated the ark ; and 
the mother of Moses the little basket in which he was 
exposed on the banks of the Nile. 

Lime was formerly called calcareous earth; its Latin 
name is calx, derived from the Arabian word kalah, to 
burn; from this comes calcine, to burn, which is applied 
to any mineral substance that has been subjected to high 
heat. 

Lime is not a simple substance, but the oxide of a 
metal called calcium- 

Lime is never found in nature free from combination, 
but always united with an acid, most frequently the 
carbonic acid. The limestone, so common in the form 
of marble quarries, limestone rocks, and chalk hills (as 
in England,) is all a carbonate of lime. 

Chemists who wish to prepare pure lime for experi- 
ments, put some pieces of white marble into a retort, and 
then heat it to a red heat; a gas is driven out, which, 
when collected, is found to be carbonic acid — when the 
gas ceases to issue from the retort, the marble, if ex- 
amined, will be found greatly changed — before, acids 
poured upon it would cause an -effervescence ; now, acids 
have no effect upon it. Its taste is very bitter and caustic. 
This substance is called quick lime, and sometimes alka- 
line earth. 

For commerce quick lime is obtained by heating lime- 
stone in large kilns. The lime, thus manufactured, is 
used for white-washing and making mortar. 



What was lime formerly called 1 
Is lime a simple substance ? 
Is it found pure in nature? 
How is pure lime prepared % 
How is the lime used in commerce obtained % 
)7* 



204 CHEMISTRY FOR BEGINNERS. 

It is probable that most who study this book, have 
observed the process which is called slacking lime. 
When white-washing is to be done, the quick lime is put 
into a tub or pail, and water gradually poured upon it. 
It absorbs a great deal of water ; about 700 times its 
own weight. The lime will not, at first, appear moistened 
by the water, because it absorbs it so rapidly ; a hissing 
noise is heard, and soon the lime begins to fall to pieces. 
So much heat is given off as to set fire to tinder. This 
is because a liquid, viz. water, becomes a solid. You will 
remember in treating of caloric, it was said, that * heat 
is given out when liquids become solids.' On contin- 
uing to add water to the lime, it forms a thick, liquid 
mixture, suitable for laying on walls with a brush. 

Lime united to water is called a hydrate ; so great is 
its affinity for water, that if it stands for a short time 
exposed to the atmosphere, it attracts moisture from it 
and slacks itself, or becomes a hydrate of lime. 

Lime is not, itself, easily fused or melted, but it greatly 
promotes the melting of other substances, and on this 
account is called vlJIux. Clay which contains lime can- 
not be used for pottery, because the vessels made of clay 
must be baked, and the lime would cause them to melt 
while they were exposed to the necessary heat. 

The carbonate of lime is marble. The sulphate of 
lime is plaster of Paris, or gypsum. The phosphate of 
lime exists in animal bones. 

The uses of lime in its various combinations, and in 
a pure state, are many and important in building, stat- 
uary, manufactures, agriculture, and medicine. 

Calcium, the metallic base of lime, was discovered by 



Describe the process in slacking lime. 
Why cannot clay, which contains lime, be used in pottery ? 
What are some of the combinations of lime, and what are their 
common names 1 
What is said of the uses of lime \ 



BARIUM. 205 

Berzelius of Sweden, in 1808, the year after the discov- 
ery of the bases of potash and soda. The weight of 
calcium is stated as 20, this being united to one atom of 
oxygen, 8, forms lime, or the oxide of calcium, which 
is represented in Chemistry by 28. 

We have now considered three of the most important 
alkaline metals, viz. potassium, sodium, and calcium, the 
others are lithium, barium, and strontium. 

Lithium, (from lithos, a stone.) 

Lithium is the newly discovered metallic basis of 
lithia, an alkali found in a mineral called petalite, also 
in the tourmaline, and some other minerals. Lithium 
is a metal of a white colour, resembling sodium in its 
properties, especially in being the base of an alkali. 

Barium. 

Barium is the metal of a mineral called barytes, (from 
the Greek barus, heavy ;) it is found in many places in 
the United States ; generally in the form of sulphate of 
barytes. As barytes combines with acids to form salts, 
viz. a nitrate, carbonate, and sulphate of barytes is very 
caustic to the taste, and gives the alkaline test with dif- 
ferent colours, it is very properly classed among the al- 
kalies, Its base, barium, is very little known. It is 
much heavier than the other alkaline metals which we 
have noticed, its atom being 70 — thus the chemical 
equivalent for barytes or the oxide of barium, one atom 

of barium being 70 
one do. oxygen 8 

- is 78 



What is said of calcium, and of the weight of its oxide 1 
Which are the three most important alkaline metals, and what 
others remain to be considered l 
What is said of lithium 1 
Describe barium. 



206 CHEMISTRY FOR BEGINNERS. 

Strontium. 

Strontium is the metallic base which forms, by its un- 
ion with oxygen, an alkaline mineral called strontia ; 
this received its name from Strontian, in Scotland, 
where it was first discovered in a lead mine. Strontia 
gives a blood, red colour to burning alcohol ; for this pur- 
pose it is sometimes used to give a peculiar effect to fire 
in theatrical representations. This mineral is said, by 
Prof. Eaton, to exist on an island in lake Erie, in the 
state of a sulphate. The base of strontia or strontium, 
was discovered in the same manner as that of the other 
alkaline metals and about the same time. The metalloids 
which remain to be examined are called earthy metals. 



CHAPTER XX. 



Metalloids, or Earthy Metals. 

We have in the last chapter considered certain sub- 
stances which before the late discoveries of Davy and 
some other Chemists were called simple alkalies ; but 
are now known to be compound, consisting of a metallic 
base united to oxygen ; these bases are called alkaline 
metals. 

There is another class of minerals which were called 
earths^ and considered as elementary substances ; these 

Describe strontium. 

What is said of the substances considered in the last chapter 1 

What is said of the minerals called earths 1 



SILEX. 207 

are now regarded as compounds, consisting of oxygen 
united to metals called earthy metals. Their oxides are 
white and of an earthy appearance, and do not generally 
exhibit strong, alkaline properties. 

MAGNESIA. 

Compound of Magnesium and Oxygen. 

The common magnesia which is used for medicine is 
an oxide of magnesium ; it is a white, soft powder, with- 
out odour or taste. This substance is very common in 
nature. It usually exists as a carbonate of magnesia, 
and is obtained pure for medicine by heating, it until the 
carbonic acid is driven off; it is then called calcined 
magnesia, and is sold in the form of a loose powder — 
the carbonate of magnesia is sold in little square cakes. 

The atom of magnesia is reckoned as 12 
that of oxygen being 8 

the equivalent of the oxide — 

of magnesium is 20 
Magnesia forms a part of the clay used for porcelain ; 
it is one of the constituents of rocks, especially soapstone, 
or, as they are called in geology, talcose rocks. These 
are remarkable for their property of resisting lire, which 
they owe to magnesia, one of the substances most diffi- 
cult to fuse of any known to the chemist. Magnesia is 
generally obtained from the sulphate of magnesia. 

SILEX. 

Compound of Silicon and Oxygen. 

Silex exists in almost all stones and earth ; it is the 
gritty part of them. Quartz is almost wholly composed 
of silex, as also flint, the Latin for which, is silex, orig- 
inally derived from an Arabian word Selag. 



What is said of magnesia 1 
Where does silex exist 1 



208 CHEMISTRY FOR BEGINNERS. 

Silex has been known from the earliest times. The 
ancient chemists called it vitriftable earth, because it 
was melted to make glass. Afterwards it was named 
silex, but is now known as the oxide of silicon ; it being 
a compound of oxygen with silicon. 

Mixed with potash or some other alkali, sand (which 
is mostly silex,) is melted to form glass ; — the dark col- 
oured glass such as you see in common junk bottles, is 
made from impure sand which is mixed with some oxide 
of iron ; the finest and clearest glass is made with pure, 
white sand. The ancients understood the process of 
making glass. Glass beads were found upon the mum- 
mies in the catacombs of Egypt, supposed to have been 
placed there 1600 years before Christ. But glass as an 
article of common use was not known until the thirteenth 
century ; about this time some of the nobles of Europe 
began to have glass windows in their houses. The arti- 
cles which are sold by jewellers as an imitation of pre- 
cious stones, and called paste, are composed of very 
fine glass, coloured by the oxides of metals — thus we 
have green in imitation of the emerald, violet of the 
amethyst, red of the ruby, and limpid of the diamond, 
the latter however, is colourless. 

Silicon, though classed among the metals, is thought by 
some chemists to be improperly placed here. Berzelius 
of Sweden, who has made many experiments upon it, 
asserts, that it bears no resemblance to any of the metals, 
but is, in some respects, like carbon and other of the com- 
bustible non-metallic substances. 



What was silex formerly called, and what is its name in 
Chemistry ? 

What is said of making glass ? 

What does Berzellius assert respecting silicon 7 ? 



SILEX. 



209 




We have here the representation of part of an elegant 
apparatus, invented by Dr. Hare, for the purpose of 
obtaining silicon, from fluo-silicic acid gas, which is 
a compound of fluorine and silicon. A bell glass is 
so fixed that it may be easily exhausted of air, by an air 
pump ; a platina wire is suspended within the bell glass 
and a cup containing potassium, hangs just below the 
wire — after the air is exhausted from the bell glass, and 
fluo-silicic acid gas admitted, the platina wire is ignited 
by an electric spark communicated to a part of the wire 
extending without the bell glass, this inflames the potas- 



Describe Dr. 
silicic acid. 



Hare's method of obtaining silicion from fluo- 



210 CHEMISTRY FOR BEGINNERS. 

sium, which burns and decomposes the fluo-silicic acid, 
giving rise to a peculiar, deep red flame, and chocolate 
coloured fumes, which condense into flakes, resembling 
(except in colour,) a miniature snow storm. On wash- 
ing the substance which is collected after this combustion, 
pure silicon, which is insoluble is obtained ; the residue 
is chiefly fluoride of potassium. 

ALUMINE. 

Compound of Aluminum and, Oxygen. 

The name alumine, is from alum, which has this 
earth for its base. Alumine is very abundant in nature, 
existing in clay, and giving it that peculiar quality 
necessary for the manufacture of porcelain. In all 
manufactures of bricks and pottery, whether of the coars- 
est kind, as the gardener's flower pots, or of the most 
beautiful porcelain vases, alumine and silex are essential 
constituents. The rudest nations know something of 
the art of making vessels of wet sand and clay, hardened 
by baking. 

Felspar one of the minerals which is of impor- 
tant use in making fine, porcelain ware, consists in 
100 parts, of silex 65, alumine 25, and potash 10. All 
these constituents are important in the manufacture of 
porcelain ware. 

Alumine is obtained by chemists for experiments, by 
the decomposition of alum (Sulphate of alumine.) To a 
solution of alum, carbonate of potash is added ; a carbon- 
ate of alumine is precipitated. The carbonic acid is 
driven off by heat, and pure alumine obtained. 

Aluminum, the metal of alumine, burns readily in the 
air ; the produce of the combustion, is the oxide of alu- 
minium or alumine. The metal is obtained by theanal- 



What is said of alumine? 

How is it obtained 1 

What is said of aluminum, and what is the weight of its oxide % 



REMARKS. 211 

ysis of the earth alumine. The combining weight of 

aluminum being 10 

oxygen 8 

The chemical equivalent of oxide of alumine is =18 

Besides the earthy metals magnesium and aluminum, 
there are four others, yttrium, the base of an earth 
called yttria, glucinum the base of an earth called glu- 
cina, zirconium the base of the earth zirconia, and tho- 
rium the base of the earth thorina ; but as these metals 
are little known and the earths in which they exist un- 
important, we shall not dwell upon them. They very 
properly demand the attention of chemists whose duty 
and whose pleasure it is to search into the secrets of 
nature, and to discover, as far as possible, the properties of 
every existing thing in her vast kingdom. 

There may be among the young persons who are gain- 
ing from this book the first elements of the science of 
Chemistry, those who are destined to make discoveries 
even greater than any preceding chemist has yet done. 

There was a time when the terms used in Chemistry 
sounded as new and strange to the ears of Davy, and 
Berzelius, and to our great American chemists, as they 
now do to you. They have attained their eminence, they 
have benefitted science but by long and patient exertion ; 
— and are there not among the youth of our country, 
those, who inspired by the example of our own scientific 
men as well as those of foreign countries, will bestir 
themselves, that they may become worthy to succeed 
those whose places will ere long be vacant, and that they 
may attain strength to gird themselves with their armour 
when they shall lay it aside forever ? 

Hopes like these encourage the author who labours 
to prepare simple works of instruction for the young. — 



What is said of some other substances which belong to the class 
we have been considering'? 
What remarks close this chapter ? 
18 



212 CHEMISTRY FOR BEGINNERS. 

This is not a field for honour and fame ; but as the parent 
toils cheerfully, to elevate his children beyond his own 
sphere, so we labour, cheered with the thought that 
our humble efforts may be the means of raising up among 
the children of our country, those who are, hereafter, to 
add to her glory and prosperity. 



CHAPTER XXI. 



Metals. 

Even young children know something of the char- 
acter of metals. They can tell their silver six-pence from 
a copper cent; and they understand that silver is more 
valuable than copper, and that gold is more valuable than 
silver ; they know that the pot is made of iron, and the 
andirons of brass, and the the shovel and tongs of steel. 
There are probably few who study this book that could 
not readily answer if asked which is the most useful 
metal. They know that iron is used for almost every 
kind of machinery, for stoves, cooking vessels, and other 
domestic utensils, as the plough, the hoe, and spade. 

Metals are not usually found pure in nature, but in the 
state of ores, that is, connected with minerals of various 
kinds, from which they are separated by different means, 
chiefly by a process called roasting — the metal being 

What is said of the general knowledge which all have of met- 
als? 
What is said of refining metals 1 



METALS. 213 

generally more easily melted than the earths or stones 
to which it is united, runs down in a liquid state, and is 
thus separated from them. In some cases as in the sul- 
phurels of metals, the sulphur is driven off or sublimed 
by heat, and the metal remains. The art of refining met- 
als is of great importance and requires much care and 
experience as well as science; it is called metallurgy. 

The knowledge of metals is of great antiquity. Tubal- 
Cain, the grandson of Methuselah, was an artificer in 
brass and iron. 

1. The metals possess a peculiar brilliancy called a 
metallic lustre. 

2. They are opaque, that is, the rays of light do not 
pass through them. 

3. They fuse or melt at different temperatures. Mer- 
cury is liquid at the ordinary temperature and even be- 
low zero. The metal called platinum can be melted 
only when exposed to a stream of oxygen gas, directed 
upon burning charcoal. Mercury is therefore the most 
fusible of the metals and platinum the least so. 

4. The metals are good conductors of heat and elec* 
tricity. 

5. Metals when combined with other substances, al- 
ways go to the negative pole of the galvanic battery. 

6. They reflect light powerfully ; this causes their 
metallic lustre. 

7. The metals were all formerly considered as heav- 
ier than water ; but since the discovery of potassium and 
sodium which are lighter than this substance, a density 
greater than water is not ranked among the properties of 
this class of elements. Platinum, one of the heaviest 
metals, is 23 times heavier than water. 

8. Metals burn brilliantly and with different coloured 
flames, when subjected to the action of galvanism. — 
Lime or the oxide of calcium can be volatilized and be- 
come vapour by a very intense heat. 

Were metals known to the ancients r l 

Mention some of the' most important porperties of metals. 



214 CHEMISTRY FOR BEGINNERS. 

9. The tenacity of metals depends on their cohesive 
attraction ; this is the power they possess of hearing 
weights. An iron wire, one tenth of an inch in diame- 
ter, will hold a weight of two pounds. Iron has more 
tenacity than any other metal. 

10. Metals are said to be ductile when they can be 
drawn out into wire. Gold and platinum are most re- 
markable for this property. 

11. Malleible refers to the property which metals 
have of being hammered or rolled into thin plates. 
Gold possesses this property in the highest degree. 

12. The colour of metals is various, but they gener- 
ally appear white, gray, red, or yellow. 

The first rude attempts made in Chemistry, were in 
the fourth century, by a set of men called alchymists, 
who laboured with great patience and perseverence in 
experiments to change the baser metals into gold. 

Metals have a strong affinity for oxygen, though in 
very different degrees. Iron attracts it from the air ; 
therefore it rusts easily, for the rust of a metal is 
caused by its union with oxygen, — rust is, therefore, 
the oxide of a metal. Gold and silver do not attract 
oxygen from the air or water ; therefore they do not rust 
easily. Gold for this reason, is used for filling cavities 
in the teeth — even the acid substances which are taken 
into the mouth with food in various ways, do not ox- 
idate gold. Silver oxidates more easily, and therefore 
when used in the same way, soon becomes discoloured 
and tarnished. 

The oxides of metals unite with acids and form salts; 
thus the sulphate of soda is a salt formed by the union 
of sulphuric acid with soda which is the oxide of sodium. 

Metals unite with each other, and form a class of bodies 
called alloys. These furnish some of the most impor- 
tant materials for the use of mankind. Brass is a corn- 



By whom were the first rude attempts in Chemistry made? 
What is said of the affinity of metals for oxygen 1 
What substances are formed by the union of the oxides of met- 
als with acids 1 



CHEMICAL RELATIONS OF METALS. 215 

pound of copper and zinc ; pewter of tin and lead ; and 
bell-metal of copper and tin. Mercury combines with 
other metals and forms amalgams* 

The ancients were acquainted with but seven metals, 
viz : gold, silver, copper, mercury, iron, tin, and lead. 
These are still the most important to mankind, notwith- 
standing many others have been since discovered. 

CLASSIFICATION OP METALLIC SUBSTANCES. 
All metals may be divided into two great classes. 

CLASS I. METALLOIDS. 

Metalloids have properties in common with the true 
metals, but they differ from them in being much lighter, 
and in having so great an affinity for oxygen that they 
absorb it from the atmosphere in a dry state. This class 
we divide into two orders. 

Order 1. — Alkaline metals, or metalloids, whose ox- 
ides are alkalies ; these are Potassium, Sodium, Calcium, 
Lithium, Barium, and Strontium. 

Order 2. — Earthy metals, or metalloids, whose oxides 
are earths ; these are Magnesium, Silicon, Aluminum, 
Ittrium, Glucinum, Zirconium, and Thorium, 

* With silver, mercury readily unites, to form an amalgam. 
Two little girls wishing to do some meritorious act in the absence 
of their mother, attempted to brighten her silver spoons by 
rubbing them over with quicksilver (mercury). At first they 
were delighted with their success, but they found, that on coming 
in contact with other substances, the spoons tarnished and looked 
dark coloured like old pewter — the little girls were then greatly 
troubled, believing they had spoiled the spoons. When their 
mother returned, they very sorrowfully informed her of the acci- 
dent; she told them that the mercury had formed an amal- 
gam with the silver, but that by heating the spoons it would be 
driven off and the silver restored ; she advised them however, not 
to attempt making experiments upon articles of so valuable na- 
ture, until they had more experience. 

What are alloys and amalgams 1 

What metals were known to the ancients 1 

Describe the first class of metals and the orders it contains. 

18* 



216 CHEMISTRY FOR BEGINNERS. 

CLASS II. THE PROPER METALS. 

This class we divide into two orders. 

Order L — Metals which are of important use to man, 
either in agriculture, for domestic purposes, or in the 
arts ; these are Platinum, Gold, Silver, Mercury, Cop- 
per, Iron, Lead, Tin, Zinc, Bismuth, Antimony, Cobalt, 
Arsenic, Manganese, and Chromium. 

Order 2. — Metals vjhich are of little use in the arts ; 
these are Palladium, Rhodium, Iridium, Osmium, Nickel, 
Cadmium, Tungsten, Uranium, Tellurium, Titanium, 
Molybdenum, Columbium, Cerium, and Vanadium. 

Of the first class, or the Metalloides, we have already- 
treated : these we found to be of little importance, except as 
exhibiting the compound nature of substances until lately 
considered simple — we therefore paid more attention to 
the oxides of these metals, than to the metals themselves. 
Potash, soda, and lime are known to almost every one, 
while potassium, sodium, and calcium, their metallic 
bases, are scarcely known beyond the chemist's labora- 
tory. Potassium is indeed of great use to the chemist, in 
enabling him to decompose other substances, a fact which 
has been already mentioned. The metals of the second 
class we shall now briefly notice. 

Platinum, was so called by the Spaniards, from the 
word plata, which, in their language, signifies silver. 
The largest mass which has been found of this metal, 
does not exceed a pigeon's egg in size. It is found in 
the vicinity of the Rio de la Plata, in South America, 
and with it are found the four new metals palladium, 
iridium, osmium, and rhodium. Pure platina is the 
heaviest of all known substances. Its specific gravity in 
comparison with water is 23. On account of its hard- 
ness, infusibility, and difficulty of being acted on by 
most substances, it is of great value for making vessels 
to be used in chemical experiments. 

How are the proper metals divided ? 

What is said of the metals of the first class 1 

What is said of Platinum 7 



GOLD — SILVER. 217 

Gold was called by the ancients the ' king of met- 
als.' Its specific gravity is 19 ; it is the heaviest of 
all known substances except platina. No substance is 
capable of such extension as gold. One ounce of gold 
can cover a wire that may be extended more than 1300 
miles. The thin sheets of gold called gold leaf are the 
lightest of all solid substances. Gold melts at 1 300° of 
F., which is above red heat. It does not oxidize by ex- 
posure to the air, heat, or moisture, and may therefore 
be preserved for ages without change. When exposed 
to the action of the galvanic battery, gold leaf burns 
brilliantly with a red light, and an oxide of gold is the 
product of the combustion. There is but one acid which 
can dissolve gold ; this is the nitro- muriatic, or a mix- 
ture of nitric and muriatic acids. Chlorine gas, warmed, 
sets fire to gold. The gold coin of the United States is 
alloyed with about one part in twelve of a mixture of 
copper and silver. The chemical equivalent of gold is 
200. 

Silver. The alchymist called silver Luna, or the 
moon, and they also called gold Sol, or the sun. Silver 
and gold were called by the ancients precious metals, 
and also noble metals. It is unnecessary to tell those 
who study this book what the colour of silver is, and 
whether it exists in the state of a liquid or a solid. Our 
silver dollars, half dollars, and the smaller pieces of 
silver coin are known to all — silver spoons, which were 
formerly only used by the rich, are now very common. 
They seem indeed to be almost an article of necessity, 
since silver is little acted upon by acids or other sub- 
stances which corrode iron and blacken pewter. From 
the fact that silver is little affected by acids, you will 
perceive that it has not much affinity for oxygen. It 
resembles gold in many of its properties. Nitric acid 
dissolves silver, forming nitrate of silver, commonly 
called lunar caustic ; lunar from the ancient name of 

What is said of Gold 1 What is said of Silver % 



218 CHEMISTRY FOR BEGINNERS. 

silver, and caustic, from its power to act upon and de- 
compose animal substances. The silver is separated 
from its combination with nitric acid by many other 
metals — if a piece of bright copper is immersed in a 
solution of nitrate of silver, it will be instantly covered 
with beautiful white crystals of silver. The chemical 
equivalent of silver is 110. 

Mercury is commonly called quicksilver ; the alchy- 
mists gave it this name because they supposed it to be 
silver in a fluid state, quickened by some substance 
which they hoped to expel, that they might obtain from 
it solid silver. The name, mercury, is from that planet, 
which the alchymists supposed had a peculiar influence 
upon the metal. This is the only metal which is fluid 
at the common temperature. You can see it in ther- 
mometers and barometers, and on the backs of looking 
glasses, where it is laid over tin-foil, making with it an 
amalgam. At 40° degrees below zero, a cold which is 
produced by mixing nitric acid and snow, mercury be- 
comes solid, and may be cut with a knife, and flattened 
by a hammer. At 656° of heat mercury can be made 
to boil, and is converted into a vapour. With oxygen 
mercury forms compounds which are of great impor- 
tance in medicine. An article in great use by phy- 
sicians, called the blue pill, is an oxide of mercury ; 
another medicinal article called red precipitate, is an 
oxide with a higher portion of oxygen. Chlorine 
forms with mercury some important combinations 
which will be mentioned under the head of chlo- 
rides. Mercury is found in a pure or native state, 
and as an ore in various parts of Europe and South 
America. This is one of the most useful metals ; its 
importance in science is very great, as without the ther- 
mometer and barometer, no precise principles could be 
established with respect to heat and its effect on substan- 



Give some account of Mercury. 



COPPER IRON. 219 

ces, or any certain observations be made of the pressure 
of the atmosphere. Medicine owes to mercury some of 
its most powerful and effective agents. 

Copper was first known in the island of Cyprus, from 
whence came the Latin name cuprum, and the English 
copper. The brass of the ancients is by some supposed 
to have been an alloy of copper and tin, but they seemed 
to have used the words, copper and brass, as synony- 
mous. The colour and other external properties of 
copper it is unnecessary to enumerate, since in the form 
of coin, as cents, and in various articles in common use 
it is known to all. Copper is not affected by the 
dry atmosphere, but when in contact with damp air, its 
surface becomes covered with the oxide of copper. It is 
combustible, and burns under the compound blow-pipe 
with great brilliancy, throwing off a green coloured 
flame. Copper alloyed with zinc forms brass, with a 
different proportion of zinc it forms pinch-beck. Cop- 
per forms various alloys with tin, as bell-metal, cannon- 
metal, bronze and a coating for the inside of copper 
vessels. Copper is found in a pure state, in the state of 
an oxide, a sulphur et, a sulphate and a carbonate. It 
should be known by all housekeepers that the compounds 
of copper are highly poisonous. Clean and bright cop- 
per vessels may be used with safety for scalding pickles 
in vinegar, for making sweetmeats, and in other culinary 
operations ; but substances should not be allowed to stand 
in them. For instance, vinegar contains acetic acid ; if 
this stands, for any length of time, in a copper vessel it 
corrodes it, forming an acetate of copper a very poison- 
ous substance known under the name of verdigris. 

Iron. The affinity of this metal for oxygen is very 
great. You will recollect that iron filings decompose 
water by uniting with its oxygen, and that hydrogen gas 
is collected in this manner. So great is the affinity of 



What is said of Copper 1 Of Iron } 



220 CHEMISTRY FOR BEGINNERS. 

iron for oxygen, that even at the common temper' tare it 
decomposes water; thus if you leave a little water t\ stand 
a few days in an iron vessel, it will appear rusted; iron 
rust is an oxide of iron. Even if left to stand dry for 
any length of time, iron will oxidate or rust by attracting 
oxygen from the air. Iron is the most useful of metals, 
and the Creator and Benefactor of man, has caused it to 
exist in great profusion in every country. Our own 
country is very rich in iron ores. New villages within a 
few years past, in consequence of the discovery of iron ore, 
have sprung up in the wilderness, and the busy hum in 
industry is now heard where silence and desolation lately 
reigned. Most mineral substances contain some iron. 
It is found in the state of an oxide, a sulphate, sulphur et 9 
carbonate, &c. ; but the oxides are the ores from which 
the metal is obtained. Iron combined with carbon forms 
steel, which is a carburet of iron ; existing with a greater 
proportion of carbon, it forms black lead or plumbago. 

Iron, as you have already seen, burns brilliantly in ox- 
ygen gas. Even in the common air, as may be seen in 
the blacksmith's shop, a bar of iron heated to a white 
heat throws out brilliant sparks when withdrawn from 
the fire. Iron is a good conductor of heat and electric- 
ity ; it is the basis of ink-powder. 

Lead, was by the ancients called saturn, who in My- 
thology, is said td have devoured his children : thus lead 
absorbs all the metals, except gold and silver. Lead is a 
soft metal of a bluish white color ; it is not very ductile, 
but very maleable, as it can be beaten into thin leaves. 
It melts easily. When black lead pencils, and sheets of 
ruled lines were less common than at present, plummets 
of lead were made by children for ruling their paper. 
These were made by melting lead and pouring it into 
moulds. Nitric acid easily dissolves lead but sulphuric 
and muriatic acids have little effect upon it. It combines 
with oxygen in three proportions forming a protoxide, 

What is said of Lead 1 



LEAD TIN. 221 

deutoxide and peroxide. * Lead is sometimes found 
pure, but more generally in combination with sulphur, 
forming a sulphuret, called in mineralogy galena. This 
is very common and when once known is easily recog- 
nized by its fine metallic lustre. 

A beautiful experiment may be made by suspending 
from the stopper of a decanter a small piece of zinc in 
a solution of the acetate, of lead ; if suffered to stand 
undisturbed a few days, a beautiful figure will be formed 
resembling a tree, this is called the lead tree. The zine 
attracts the acetic acid from the solution of acetate of 
lead and the lead being precipitated from this combina- 
tion collects upon the zinc, branching forth in various 
directions. The salts of lead are mostly very poison- 
ous. 

Tin. On account of its splendid appearance like that 
of the beautiful planet Jupiter, it was by the alchy- 
mists called by that name ; they thought there was some 
intimate connection between the planets and the metals, 
and that the number of each being equal, (as they then 
reckoned but twelve of each,) they thought each planet 
had its metal, and each metal its planet. These strange 
notions of the people in remote ages seem to us quite 
ridiculous, but we must recollect that with all our boasted 
knowledge, those who come after us may be as much 
surprised at many of the opinions we now hold, as we 
are at those of our predecessors. 

Tin is very flexible ; it dilates much by heat and is 
among its best conductors. It attracts oxygen from the 
air, less freely than some of the metals, of course it does 
not rust so easily. It melts more easily than any metal 
except potassium, sodium, and mercury; lead stands 
next below tin in fusibility. Tin burns brilliantly in 
the focus of the compound blow-pipe with a lively white 

* For an explanation of these terms see oxides. 

Describe Tin, 



222 CHEMISTRY FOR BEGINNERS. 

flame; the result of the combustion is a white oxide of 
tin. Tin combines with but two simple combustibles, 
sulphur and phosphorus. An alloy of tin with zinc, 
and sometimes with other substances, forms pewter. 
Tin is not found in this country ; the most important tin 
mines known are in Cornwall, England. 

Zinc ; this metal has a bluish white colour, and a 
strong metallic lustre ; it is obtained from two ores, the 
carbonate of zinc, called calamine, and the sulphuret of 
zinc, called zinc-blende. The zinc of commerce was 
formerly brought entirely from China, as the secret of 
obtaining it from its ores was not known to Europeans. 
It is now manufactured in Europe in great quantities ; 
and exists in many places in the United States. Zinc 
has a strong affinity for oxygen, and is therefore often 
used for obtaining hydrogen, by the decomposition of 
water; it is for the same reason used for the positive 
side of the galvanic battery ; — you know that oxygen al- 
ways goes to that side. Zinc is very combustible ; if a 
small quantity is put into a crucible, it may soon be 
heated by a common furnace and made to boil ; a little 
more heat causes it to burn ; a light white substance 
rises and floats about the room — this was formerly called 
white nothing, and 'philosopher' s wool. It is the oxide 
of zinc. 

Bismuth is a metal of a reddish white colour ; it is 
very brittle and fusible. A preparation of bismuth 
forms the pearl powder, which has already been 
named as being in use as a cosmetic r and which be- 
comes dark coloured by the vapour of sulphur, hy- 
drogen and phosphorus. A solution of the nitrate of 
bismuth forms a sympathetic ink ; letters written with 
it although at first invisible, when exposed to sul- 
phuretted hydrogen gas become distinct and legible. 
Bismuth is not found abundantly; one locality only 
is known in the United States, this is in Connect!-- 

What is said of Zinc % Of Bismuth-'? 



ANTIMONY — COBALT. 223 

cut, where it is found in connection with silver, galena, 
zinc blende and some other minerals. 

Antimony. The name of this metal is said to be de- 
rived from anti, against, and monakos, a monk, it having 
been first applied to medicine by Basil Valentine a Ben- 
edictine monk, who, using it injudiciously among the 
brethren of his order, killed many of them. It is of a green- 
ish white colour, and very brittle ; it is seldom found 
pure in nature. The sulphuret is the most abundant of 
its ores. It is a constituent of the metal of which prin- 
ter's types are made. With tartaric acid, (an acid ob- 
tained from the fermentation of grapes,) and potash, an- 
timony forms an important medicinal substance called 
tartar emetic. 

Cobalt, is found in connection with ores "of iron, cop- 
per, and arsenic, and is separated from them by sub- 
jecting the ores to a high heat. These ores were used 
in Europe, as early as the fifteenth century, for the pur- 
pose of colouring glass blue; but it was not, until the 
last century that they were known to contain a peculiar 
metal. Solutions of cobalt form sympathetic ink, that is, 
an ink which is invisible, until a certain process is gone 
through. The nitrate of cobalt, when pure, is of a beau- 
tiful blue color, or if iron is present, of a pea green ; 
when much diluted it is a pale rose or pink. Writing 
with this solution appears invisible on white paper when 
cold, but when held to the fire, it takes a blue or green 
tinge, and the writing is legible. * Paper fire screens 
are sometimes adorned by drawings of trees, whose 
trunks and leafless branches, are sketched in india ink, 
or other appropriate colours (representing a winter scene) 
and the foliage is made with the invisible solution of 
cobalt ; on bringing it near the fire, the green leaves at 
once appear, (and spring returns. 5 # ) It is supposed that 

* Silliman's Elements of Chem. 

What is said of Antimony 1 Of Cobalt 1 
19 



224 CHEMISTRY FOR BEGINNERS. 

this effect is caused by the agency of oxygen, in some 
manner not well understood. iYJost of the cobalt of 
commerce is obtained from a combination with arsenic, 
called arsenical cobalt. In Saxony, this manufacture is 
very extensive, and carried on by criminals who are con- 
demned to this labour for crimes, that by law, deserve 
death. The fumes of the arsenic which is a deadly 
poison, render the business destructive to health and life, 
and wretched must be the existence dragged out by the 
miserable beings who are thus cruelly punished. The 
children of luxury when partaking of their rich bever- 
age from porcelain cups painted with the beautiful blue 
of cobalt, think not of the dreadful sufferings their 
fellow creatures have endured in order to procure this 
costly embellishment. An oxide of cobalt mixed with 
silex forms a substance called zaffre ; this heated with 
sand and potash forms a beautiful blue glass called smalt ; 
and this latter powdered very fine is called powder-blue. 
This is said to be more delicate than indigo for bluing 
muslins and laces. ' The name, cobalt, is said to be de- 
rived from cobalus, the supposed demon of mines, who 
opposed the operations of the miners, and this metal 
appearing at first mysterious and untractable, was nick- 
named cobalt* It is found in Chatham in Connecticut, 
and Franconia in New Hamshire. 

Arsenic ; this metal is supposed to have derived its name 
from an arabic word, arsanek, signifying strong and dead- 
ly qualities. Arsenic is obtained by roasting the ores of 
cobalt ; as it is volatile, it vapourises and condenses in re- 
ceivers prepared for that purpose. Arsenic may be de- 
tected, by its strong smell of onions or garlic, when thrown 
upon burning coals ; in burning, it unites with oxygen 
and forms the oxide of arsenic, or as some consider it 
arsenious acid. With the alkalies, this forms salts called 
arsenites. The deutoxide of arsenic is this metal with 
a greater portion of oxygen, by some considered as arsenic 



What is said of Arsenic ? 



MANGANESE CHROMIUM. 225 

acid ; combined with alkalies, as potash and soda, it forms 
salts called arseniates. The equivalent number of the 
metal arsenic is 38. King's yellow — which is consid- 
erably used in painting, both in water colours and oil, is 
made of a sulphuret of arsenic, called orpiment* Peo- 
ple who make use of these colours, ought to be very 
careful never to put paint brushes into the mouth as most 
of the colours are based upon poisonous substances. 

Manganese. The affinity of this metal for oxygen is 
such that it is never found in a mere metallic state, but, 
always as an oxide. It is found in connection with iron 
ore which it resembles in colour, and other external 
properties. You will recollect that the peroxide of this 
metal, (that is, the oxide with the most oxygen,) gives off 
oxygen when heated to a red heat. The equivalent of 
manganese is 28. It is not of much use, except in 
Chemistry to furnish oxygen and chlorine gases. The 
latter gas is obtained by the agency of manganese on 
principles, respecting which, chemists have not agreed. 
The peroxide of manganese, and muriatic acid (hydro- 
chloric) are put into a vessel and exposed to heat ; chlo- 
rine gas is then given off. It is supposed that the mu- 
riatic acid decomposes; that its hydrogen unites with 
the peroxide of manganese, and one part of the liberated 
chlorine combines with the manganese, while the other 
portion is disengaged ; there is then in the process a 
formation of water, of the chloride of manganese, and 
a disengagement of chlorine.* On account of the utility 
of manganese in disengaging chlorine from muriatic 
acid and common salt, it is indispensable in the bleach- 
ing processes of manufactories. 

Chromium ; the name of this metal is from the Greek 
kroma, colour, because it is remarkable for giving colour 
to its combinations. The metal is of no use in its pure 

* See Dictionary of Chemistry, page 159. 
What is said of Manganese? Of Chromium 1 



226 CHEMISTRY FOR BEGINNERS. 

state; it is generally found combined with oxygen. 
There are two oxides of chromium, the protoxide which 
is green, and the deutoxide which is brown ; the chromic 
acid, which is the same metal with a higher portion of 
oxygen, is scarlet. The compounds of this acid with 
bases are called chromates ; these salts are all coloured. 

The metal, chromium, was first obtained by the cele- 
brated French chemist, Vauquelin, from the chromate 
of lead, a brilliant yellow substance, used as a paint 
under the name of chrome yellow. Chromium is the col- 
ouring matter of many minerals ; the emerald is coloured 
green by its oxide, the ruby red by its acid. Chromate 
of iron is found in marble and serpentine, and in con- 
nection with the oxide of iron is thought to produce the 
green and most other colours with which they are vari- 
egated. 

We have now given a sketch of the principal charac- 
teristics of the most important metals We shall do little 
more than name the metals of the 2d order of the class 
of proper metals. 

The following metals have been found in connexion 
with the ore of platinum. 

1. Palladium, was discovered in 1803 by Dr. Wol- 
laston. It is a very rare metal. It was named after the 
late discovered planet, Pallas. 

2. Rhodium, was discovered by Dr. Wollaston about 
the same time that he found palladium, and in the same 
metal. It has been combined with several of the metals 
but it is too rare to be applied to any use. Its name is 
from the Greek rodon, a rose, on account of the rose col- 
our of its salts. 

3. Iridium, a metal found in connexion with another 
called osmium, in the ore of platinum. The name 
(from Iris the rainbow,) is given in allusion to the 
changeable colour of some of its solutions. Accor- 

What orders are we now to consider 1 

What four metals have been found in connexion with platinum 
ore? 



NICKEL CADMIUM. 227 

ding to Berzelius, as quoted by Silliman, 'solutions 
may, without the aid of foreign matter, be obtained 
with all the colours of the rainbow/ 

4. Osmium, from the Greek osme, odour, is named in 
allusion to the peculiar smell of its oxide, which somewhat 
resembles chlorine. It is found only in platinum ore, 
either combined with other metals, or with iridium. 

The four metals we have just described, viz. palladi- 
um, rhodium, iridium and osmium are called platinifer- 
ous minerals, because they are found with platina. The 
method of obtaining them from their combinations is 
very complicated, and shows the great accuracy and del- 
icacy of chemical analysis. 

Nickel is found in connexion with the ore of cobalt ; it 
also exists with iron in what are called meteoric stones* 
(substances which occasionally fall to the earth from the 
surrounding atmosphere, and whose origin is unknown). 
Nickel is a white metal, somewhat like silver in appear- 
ance. It is thought to possess magnetical attraction, a 
property which is possessed by no other metals except 
iron and cobalt. It forms a green oxide of nickel, when 
heated in the air, or with oxygen. Pure nickel is never 
found in nature ; it is obtained from its ores hy a com- 
plicated process. Although a highly valuable metal, it 
is too rare and costly to be applied to use in the arts. 

Cadmium was first discovered in 1817, in an oxide of 
zinc. It is a white, brilliant metal resembling tin ; it 
receives a high polish. Though an interesting metal it 
is not yet obtained in sufficient quantities to cause it to 
rank among the useful ones. It has not been found in 
this country, though it is thought that it may exist with 
zinc in the Missouri lead-mines. 

* Silliman observes that c large masses of meteoric iron, in Si- 
beria, Peru, Louisiana, &c. have lain in the open air apparently 
from age to age without rusting, or only superficially.' It is sur> 
posed that the nickel they contain prevents their rusting. 

Describe Nickel. What is said of Cadmium ? 
19* 



228 CHEMISTRY FOR BEGINNERS. 

Tungsten. The name^f this metal signifies, in the 
Swedish language, heavy stone. It was first discovered 
in a mineral from Sweden, called in mineralogy, wolf- 
ram, but known in Chemistry as the tungstate of iron 
and manganese. There is a combination of oxygen and 
tungsten to fornl tungstic acid ; this acid it is, which, 
with bases, forms tungstates ; of these there are some 
with alkaline, and some with metallic bases. The metal 
tungsten is said by Silliman to exist in Connecticut. 

Uranium, was by its discoverer named in 1789 from 
the Greek ouranos, the heavens. It was found in a 
mineral called pechblend, which is the oxide of urani- 
um. It is obtained by calcining the ore or driving off 
the oxygen with heat. Combined with carbonic acid it 
forms chalcolite, or green mica. 

Tellurium was named in 1789, by Klaproth, the dis- 
coverer of uranium from tellus, the earth ; thus follow- 
ing the example of the ancients, who named minerals 
from the planets. Tellurium is a brilliant metal ; it 
burns with splendor in oxygen gas. Silliman thinks it 
exists in Connecticut in connexion with the ore of tungs- 
ten. 

Titanium resembles bright copper in its colour and 
lustre ; its crystals were at first mistaken for iron pyrites 
in England and Scotland. It is found in primitive 
rocks, and exists in many places in the United States. 

Molybdenum, is so called from a Greek word signify- 
ing lead; this w r as long supposed to be the same sub- 
stance as black lead or plumbago. It does not exist pure 
in nature, but is found either as a sulphuret of molybde- 
num or a molybdate of lead ; the latter substance is com- 
posed of molybdic acid and lead. 

Columbium was first sent by Governor Winthrop of 
the Massachusetts colony, to Sir Hans Sloane, the foun- 
der of the British Museum. The name was given in 

What is said of Tungsten ? Of Uranium 1 Of Tellurium 1 
Of Titanium 1 Of Molybdenum 1 Of Columbium 1 



CERIUM — VANADIUM. 229 

honour of the discoverer of America. The metal is of a 
dark gray colour. It was formerly called tantalium. 

Cerium was discovered in 1804, and afterwards in- 
vestigated by Vauquelin. It is found in a mineral 
called cerite which is the oxide of cerium. In some 
respects the metal is said to resemble iron, though it is 
harder and whiter. 

Vanadium. This is the most recently discovered 
metal. It was found in 1830, in connexion with iron 
ore, by a director of the school of Mines of Fahlun, in 
Sweden. This metal is said to resemble chromium, and 
therefore easily mistaken for it. Since its discovery, it 
has been found in lead ore of Mexico, in which, twenty 
years before, a professor of Chemistry asserted that he 
had found a new metal ; but he was contradicted in this 
by another chemist, to whom he submitted some speci- 
mens, who said it was merely impure chromium. Com- 
bined with oxygen it forms vanadic acid, and this with 
bases forms salts called vanadiates. 

The pupil will observe that in the arrangement we 
have made with respect to the two orders of proper met- 
als, there is nothing which need to confuse his mind with 
respect to any other arrangement which he may after- 
wards meet with in books of Chemistry. The division 
of metals into such as are useful in the arts, and such 
as are not, seemed the most simple and easy to be un- 
derstood of any that could be made ; and you will per- 
ceive that there is at present, a broad and plain distinc- 
tion between them in this respect ; — though it is very 
probable that in the progress of science, means will be 
found for obtaining in plenty, some of those rare metals 
which are now scarcely known but in name, and that 
they may be destined to become as common for useful 
and ornamental purposes as any which are now in use. 



What is said of Cerium'? Of Vanadium 1 
What is remarked respecting the arrangement of metals made 
in this book 1 



230 CHEMISTRY FOR BEGINNERS- 



CHAPTER XXII. 



Oxides. Chlorides. Salts. 

Our enumeration of elements or simples substances 
is now completed ; they consist of imponderable bodies, 
as Caloric ; Supporters of Combustion, as Oxygen ; 
Combustibles, not metallic, as Hydrogen ; Metalloids, as 
Platinum ; Proper Metals, as Iron. 

From these substances are formed every thing, on and 
around the earth that we have any knowledge of — the 
rocky foundations of the earth, the air, the water, the 
vegetable creation, and the animal frame — every product 
of land or sea, of heaven and earth, so far as science has 
discovered, may be resolved into two or more of these 
elements. 

BINARY COMPOUNDS, 

Consisting of two elements. 

When any two elements are united they form what is 
called a binary compound, (from the Greek bis, two.) 
They are of three kinds: 1. acids; 2. oxides; and 3. 
those which are neither acids nor oxides. 

Acids. 

Acids were long supposed to be produced by oxygen 
only, as its name signifies the producer of acids ; but 

What classes do the elements or simple substances in nature 
consist of 7 

What are all the substances on, and around the earth composed 
ofl 

What is a binary compound, and how many kinds of binary 
compounds are there 1 

What is said of acids ? 



OXIDES. 231 

chlorine and the other supporters of combustion, together 
with hydrogen, have been found to form acids. 

Nitric acid is composed of nitric acid and oxygen, 

Sulphuric acid " sulphur and oxygen, 

Carbonic acid " carbon and oxygen. 

Muriatic acid, which is composed of hydrogen and 

chlorine, is among the most powerful of the acids, though 

it contains no oxygen. Prussic acid * (hydro-cyanic) is 

a compound of cyanogen and hydrogen, and is also a 

very powerful acid. 

Oxides. 

Oxides are formed by the union of oxygen with ele- 
ments ; the metallic oxides were formerly called metallic 
ashes and burnt metals. You have seen that the non- 
metallic substances, nitrogen, phosphorus, &c, form 
acids by their union with oxygen ; but that a lower pro- 
portion of oxygen produces with them compounds which 
do not affect vegetable colours, nor give other acids 
tests ; these are, therefore, called oxides, as nitric oxide, 
&c. ; water is the deutoxide of hydrogen. 

The metallic oxides are formed by the union of oxy- 
gen with a metal ; thus when iron or copper wire is 
burned in oxygen we have an oxide of iron, or an oxide 
of copper. 

Some metals unite with oxygen in more than one, and 
some, in more than two proportions ; thus we have prot- 
oxide for the first degree of oxidation, deutoxide for the 
second, and tritoxide for the third ; peroxide signifies 
the highest state of oxidation of which the substance is 
capable. 

The most important metallic oxides are those which 
we have already noticed under the head of alkaline 

* Prussic acid is not however a binary compound, since its base 
cyanogen is composed of two elements. This is a ternary com- 
pound or one that consists of three elements. 

What is said of oxides ? 



232 CHEMISTRY FOR BEGINNERS. 

metals, as the oxide of potassium, the oxide of sodium, 
&c. j which are the chemical names for potash, soda, &c. 

Chlorides. 

Another important class, of binary compounds are the 
chlorides ; these consist of substances formed by the 
union of chlorine with different metals. They were for- 
merly ranked among salts ; — but salts are formed by the 
union of oxides, being composed of four elements ; while 
chlorides consist of but two elements. When common 
salt was named muriate of soda, it was supposed that 
muriatic acid was composed of a base, muriatium, united 
to oxygen, and that this acid combined with soda formed 
the salt : but since muriatic acid is found to consist of 
hydrogen and chlorine, and soda is found to have a me- 
tallic base, dry salt is called chloride of sodium. A so- 
lution of salt, the hydrogen of the water goes to the 
chlorine, forming hydro-chloric or muriatic acid, and 
the oxygen of the water goes to the sodium, forming 
the oxide of sodium or soda, and thus presents a proper 
muriate of soda. Dry, common salt does not then be- 
long to the salts known in Chemistry, but to the chlo- 
rides. 

Chloride of sodium, or common table salt, consists of 
one proportion of sodium whose 

combining number is 24 

one of chlorine " 36 

60 is the number 
representing salt. Of the important uses of this sub- 
stance in preserving meat and preparing food it is un- 
necessary to remark. It is of great use in bleaching 
manufactories, by furnishing chlorine. It is highly es- 
teemed as a preventive of contagious diseases, and was 
used very extensively and with great success, under the 

What are chlorides, and why are they not properly salts? 
Describe the chloride of sodium. 



quarternary compounds. 233 

name of chloride of soda, during the late alarming prev- 
alence of the cholera in the United States. 

Chloride of calcium is composed of chlorine and the 
metallic base of lime. Slacked lime which is called a 
hydrate of lime, unites with chlorine gas and forms a 
hydrated chloride of lime; this is called bleaching pow- 
der, and is useful for many of the purposes to which the 
chloride of soda is applied; it is less expensive. 

Proto- chloride of mercury forms a very important 
medicine called calomel. The deuto- chloride of mercury 
is commonly called corrosive sublimate ; it is a deadly 
poison, and is used for destroying insects and bugs. 

There are chlorides of silver, of gold, and of other 
metals, which furnish interesting subjects for the obser- 
vation of the chemist, but our limits will not permit us 
to examine them. 

Fluorine, iodine, and bromine, the three supporters of 
combustion in the class with oxygen and chlorine, form ? 
with metallic bases, fluorides, iodies, and bromides. 

Among the binary compounds are carburets, sulphu- 
rets, phosphorets, <fyc. ; the termination uret, you will 
recollect, is applied to combinations of the non-metallic 
substances among themselves. 

QUARTERNARY COMPOUNDS, 
Consisting of four elements. 

The powerful properties of acids have been explained: 
alkalies (or the oxides of alkaline metals), possess prop- 
erties directly opposed to these — acids are compounds 
consisting of oxygen or some other acidifiable element 

Describe the chloride of calcium. 

What are the chlorides of mercury commonly called 1 

Are there any other chlorides besides those already described 1 

What compounds are formed by fluorine, iodine, and bromine, 

with metallic bases? 
What other binary compounds are there, besides those which 

have just been named 1 
How do alkalies and acids differ ? 



234 CHEMISTRY FOR BEGINNERS. 

united to a base ; thus nitric acid is composed of oxygen 
and nitrogen. Alkalies are composed of metals united 
to oxygen, as potash which consists of oxygen and the 
metal potassium. Acids turn vegetable blue colours, 
red ; alkalies turn them green. Acids (with very few 
exceptions) taste sour, alkalies have a pungent taste of a 
very different kind. Acids are attracted to the positive 
pole of the galvanic circle, alkalies to the negative. 

The union of acids and alkalies forms salts, which in 
most cases bear no resemblance to the substances of 
which they are composed. These are called neutral 
salts. But there are some cases when the salt appears 
to partake of the character of the acid, and others in 
which the alkali seems to predominate. 

Action of water upon the salts. Some of the salts 
can be dissolved in water, as the sulphate of soda 
(Glauber's salts) ; others are insoluble, as marble (car- 
bonate of lime). This property depends on their degree 
of affinity for water, and their cohesion. They are more 
soluble in warm than cold water. 

Action of ice. When pounded ice is mixed with a 
soluble salt, the one melts rapidly, and the other is 
quickly dissolved ; cold is produced in consequence of 
the absorption of heat from surrounding bodies in caus- 
ing solids to pass to a liquid state. Thus in making 
iced cream, common salt and ice are placed over the ves- 
sel containing the cream to be congealed. 

Action of air. Some salts absorb moisture from the 
air and become damp ; this is called deliquescence. 
House-keepers know that pearlash, (carbonate of potash,) 
if left exposed to the air, soon becomes wet and at length 
wholly dissolved. Some salts fall to powder on expos- 
ure to the air ; this is called effloresence. 

How are salts formed 1 

What is said of the action of water upon salts ? 

Of the action of ice upon salts 7 

Of the action of air upon salts ? 



SALTS. 235 

Action of ftre. When submitted to the action of fire 
some salts lose their water of crystallization, and break 
in pieces with a crackling noise ; this is called decrepi- 
tation ; you can observe an instance of this, by throwing 
a piece of common salt upon burning coals. 

Action of galvanism. When submitted to galvanic 
action, the acid of the salt goes to the positive and the ox- 
ide to the negative pole ; when the action is powerful the 
acid is decomposed and its oxygen then goes to the posi- 
tive and its metal to the negative pole. 

Actions of metals upon solutions of the salts. Metals 
have a powerful action upon the solutions of some of the 
salts. When a piece of zinc is introduced into a solu- 
tion of the acetate of lead, the acetic acid having a 
greater affinity for the zinc, leaves the lead, which, be- 
ing precipitated or thrown out of the solution, attaches 
itself to the zinc forming what is called the lead tree, al- 
ready named under the article lead. There is some- 
thing very curious in this process ; as soon as the zinc 
unites with the lead, a new principle begins to operate ; 
viz. that of galvanism. The two metals form the poles 
of the galvanic pile, of which the zinc is positive ; the 
precipitating metal being always positive, and the pre- 
cipitated negative. From hence arises the decomposition 
of the water, of the salt which was dissolved in it, and of 
the oxide of the metal. This property of metals to act on 
solutions of salt was found very destructive to ships with 
copper bottoms ; as the plates of copper, in consequence 
of decomposing the salts held in solution by the water, 
became corroded by the action of the acids thus set at 
liberty. Sir Humphrey Davy again brought his sci- 
entific knowledge into the service of mankind ; — by stud- 



What is said of the action of fire upon salts 1 
What is said of galvanic action upon salts 1 
Of the action of metals upon salts 1 
20 



236 CHEMISTRY FOR BEGINNERS, 

ying into the subject, he ascertained that a double lining 5 
of zinc and copper would change the electrical state of 
the copper, and prevent its being injured by the decom- 
position of sea water. 

Action of the oxides upon the salts. Some oxides 
when brought in contact with the salts, in a state of solu- 
tion, take the place of those which formed the bases of 
the salts. Sometimes the new oxide displaces a part of 
the base and combines with the salt, thus forming a 
double salt, as alum, which is a sulphate of alumine and 
potash. 

Nomenclature of the Salts. 

Names given to the salts. The acids which contain 
most oxygen, terminate in ic, those with a lower portion 
of oxygen terminate in ous ; thus, we have sulphuric 
and sulphurous acids. The acid whose name ends in 
ic, forms a salt whose name terminates in ate ; while 
the acid whose name ends in ous, forms a salt whose 
name terminates in ite. Thus, sulphuric acid forms 
with bases salts called sulphates, and sulphurous acid 
forms sulphites. 

The chemical name of the salts, shows of what they 
are composed, and are therefore preferable to names 
which were merely fanciful or arbitrary ; thus Plaster 
of Paris (or gypsum,) is now sulphate of lime, Epsom 
salts is now sulphate of magnesia, Salt petre is nitrate, 
of potash, SfC. 

The salts are divided into genera and species ; a ge- 
nus contains such species as are formed by one acid with 
different bases. We will consider some of the most im- 
portant genera with some of their species. 



What is said of the action of oxides upon salts 1 
By what rule are the salts named 1 
Why are chemical names the best to distinguish salts ? 
How are the salts divided 1 



SALTS CARBONATES. 237 

Genera of Salts. 

Borates. Combinations of boracic acid with different 
bases. This genus is divided into sections ; — Neutral 
borates are such salts as exhibit neither acid or alkaline 
properties. Sub*-borates are deficient in acid, or show 
an excess of the base exhibiting alkaline properties, — 
they are by some, called basic salts. The sub-borate of 
soda is the most important of them. This is called bo- 
rax, and by its decomposition affords boracic acid. Bo- 
rax is useful in promoting the melting of other oxides, 
and forms with them glass of various colours. 

Carbonates. Combinations of carbonic acid with dif- 
ferent substances. Most of the salts of this genus are de- 
composed by heat, which expels the acid. Most of the 
acids decompose the carbonates, by uniting with their 
bases and thus disengaging carbonic acid — any mineral 
that contains carbonic acid, will effervesce with acids. 
The effervescence is caused by the escape of the car- 
bonic, as the lime unites with the new acid. 

The most important species found in the genus carbon- 
ates, are, 

1. Carbonate of Lime; this is one of the most abun- 
dant of all mineral substances. It is known under va- 
rious names, as limestone, chalk, marble, &c. It exists 
in some waters in a state of solution. Pure or quick 
lime is obtained by calcining or heating the carbonate, 
and thus expelling the acid. 

This salt is composed of 

one proportion of carbonic acid =22 
one " " lime 28 

The representative number of the salt 50 

* Sub is from the Latin, and signifies under ; sub salts are those 
which do not contain sufficient acid in their composition to neu- 
tralize the alkaline qualities of the base. 

Describe the genus borates. 

Describe the general character of the genus carbonates. 

Describe the species carbonate of lime. 



238 CHEMISTRY FOR BEGINNERS. 

Chemistry shows us that nearly half of the matter of 
the solid rocks of limestone is a gas. 

2. Carbonate of Potash is made from the ashes of 
vegetables; the strong ley obtained from the ashes, is 
evaporated till a dry substance of a dark red colour is 
left. This is potash, or the oxide of potassium ; it is 
very caustic at first, but loses this property on being ex- 
posed to the air from which it attracts carbonic acid, and 
becomes a carbonate of potash. Pearlash is a more 
pure carbonate of potash ; it is now generally sold at 
the shops under the name of Sal-eratus. The bi ^car- 
bonate of potash, is formed by passing carbonic acid 
into a solution of the carbonate which thus receives a 
second portion of the acid. This is reccommended as a 
valuable medicine for removing acidity in the stomach. 

3. Carbonate of soda, is prepared like the salt we 
have just described, except that the ashes of sea-weed, or 
vegetables growing near salt-water are used. It is com- 
monly known by the name of Soda. 

4. Carbonate of magnesia, is sold by apothecaries in 
cakes or lumps. — It is used in medicine, but is less valua- 
ble than calcined magnesia, or that from which the 
carbonic acid has been expelled. 

5. Carbonate of copper, is found native in a mineral 
called malachite of a beautiful green colour ; it also col- 
lects like a green rust upon copper vessels exposed to 
the air. The blue paint verditer, is an impure carbon- 
ate of copper. 

6. Carbonate of* Lead, is the white lead used by paint- 
ers ; it is prepared by exposing sheet lead to the vapour of 
vinegar ; the fumes of the acid, first form the oxide of 

* From the Greek bis, two. 



Describe the species carbonate of potash. 
What is said of the carbonate of soda 1 
What is said of the carbonate of magnesia'? 
Of the carbonate of lead 1 



SALTS CHLORATES. 239 

lead, and this gradually attracts carbonic acid, from the 
atmosphere and becomes a carbonate. * 

7. Carbonate of barytes, was discovered by Dr. With- 
ering in the lead mines in the north of England, and is 
known in mineralogy by the name of witherite. 

8. Carbonate of Ammonia, is a white powder used 
in smelling bottles under the name of salts of hartshorn. 
It is the product of animal substances, by the action of 
heat. 

II. Genus chlorates. The salts of this genus are 
composed of chloric acid and bases ; they are never 
found in nature, but are the product of art. They 
were formerly called oxymuriates. The difference be- 
tween them and chlorides may be thus stated ; — a chlo- 
ride is a binary compound, consisting of chlorine and 
a simple element ; chlorates are quaternary compounds, 
consisting of chloric acid, (chlorine and oxygen) united 
to an oxide, which consists of two elements. It might be 
said here are but three elements, oxygen and chlorine, 
and the base of the oxide, as the oxygen of the oxide can- 
not be called a fourth element, when it has been already 
counted — but you must observe that in the salts, the four 
elements are not all mingled together, but two binary 
compounds, viz. ; the acid and oxide must unite to form 
them ; and thus we consider the oxygen of the acid and 
that of the oxide as distinct, though not different ele- 
ments. From what has been observed you will perceive 
that chlorides differ much in their composition from 
chlorates ; the former are sometimes improperly classed 
among salts, but do not belong to them more than acids, 
oxides or any other binary compound. 

* Although carbonic acid is not a constituent portion of the 
atmosphere, yet some portion always exists in it. 

What is said of the carbonate of barytes % 
Of the carbonate of ammonia ? 

What is said respecting the general characteristics of the genus 
chlorates 7 

20* 



240 



CHEMISTRY FOR BEGINNERS. 



We shall mention bat one species under this genus. 

Chlorate of potash, when thrown upon burning coals, 
parts with the oxygen of its acid and of its oxide, and 
becomes chloride of potassium ; on account of parting 
with so much oxygen this substance has a powerful effect 
on combustion. When mixed with sulphur or any res- 
inous body, it will inflame and burn spontaneously. 
Allumetts, or matches, are made of little sticks of pine, 
the ends of which, are coated with a kind of paste, 
formed of chlorate of potash and resin ; on being lightly 
plunged into a little vial of sulphuric acid, fire bursts 
forth. This chlorate enters into the composition of most 
of that kind of substances called fulminating powders, 
on account of the noise produced in their explosion ; 
Carbon, sulphur, and phosphorus are used with it in 
these compositions. Attempts have been made to use 
chlorate of potash in gun powder, but it is found to be so 
sudden in its operation as to render it a very dangerous 
instrument to the operater. 

This salt is obtained by saturating a solution of sul- 
phate of potash with chlorine gas. The figure repre- 




Describe the chlorate of potash. 



SALTS — HYDRO-CHLORATES. 



241 



merits a part of the apparatus used for this purpose. 
A is the outer one of three jars filled with a solution of 
sulphate of potash. The retort contains the oxide of 
manganese upon which muriatic acid being* poured, chlo- 
rine gas is disengaged and passes through the neck of 
the retort to the ball B, and from the trumpet shaped 
tube into the liquid of the inner jar, after saturating the 
liquid in all the jars, the gas which is not absorbed 
escapes through the pipe P. The pipe E, conducts off 
any superfluous gas into vessels prepared to receive it. 

The saturated solu- 
tion of chlorate of 
potash must be crys- 
talized in order to 
obtain the salt in its 
purest state. The 
figure represents the 
manner of doing this. 
The solution requires 
to be filtered or strain- 
ed and this must be 
done while it is hot. 
For this purpose Dr. 
Hare contrived a 
large vessel of sheet 
tin containing an aper- 
ture for a funnel, and 
another to serve the 
purpose of a chimney 
by conducting off the smoke of the lamp below. This 
lamp keeps the water hot with which the tin vessel is fil- 
led; the hot water surrounding the solution to be strained, 
prevents its cooling. A coarse fibrous paper is laid 
into the funnel for the solution to filter through ; it is 
received in the decanting jar beneath, and there crystal- 
lizes in beautiful, silvery white plates. 




By what method is the chlorate of potash obtained ? 
How are crystals of chlorate of potash obtained 1 




242 CHEMISTRY FOR BEGINNERS. 

Hydro-chlorates differ from chlorates in being formed 
with hydro-chloric acid, (muriatic acid,) instead of chlo- 
ric acid. These substances were called muriates before 
the discovery of chlorine. 

The hydro- chlorate of ammonia, or muriate of ammo- 
nia, is the salt usually called sal-ammoniac ; it may be 
formed. by mingling, in equal volumes, in a dry glass 

vessel, the two 
gases, ammonia 
and muriatic acid. 
Thus A and B 
represent bottles 
containing the 
two gases, and C 
the glass bottle in 
which solid mu- 
riate or hydro-chlorate of ammonia, being formed by 
their union, is precipitated in snow white vapours. 

The hydro- chlorate of soda (or muriate of soda) is 
common salt in solution ; the manner in which it differs 
from the chloride of sodium has been already explained 
in treating of that substance. 

III. Genus Nitrates. There are only four nitrates 
found in nature, those of potash, lime, soda, and magne- 
sia. They are found in solution, in water in the earth 
of old cellars, and under the floors of stables. The most 
important species of this genus are 

1. Nitrate of 'potash or salt-petre; this has been already 
noticed under the head of potash. The nitrates resem- 
ble chlorates in many of their properties, particularly in 
easily parting with oxygen, which renders them impor- 



How do hydro-chlorates differ from chlorates, and what were 
they formerly called % 
How is the hydro-chlorate or muriate of ammonia obtained? 
What is the hydro-chlorate of soda 1 

How many nitrates are there and how do they exist in nature? 
What is said of the nitrate of potash 7 



SALTS SULPHATES. 243 

iant agents in fulminating or detonating powders. The 
nitrate of potash is an important constituent of gun- 
powder. It is of general use in putting up meat for 
salting, through the fibres of which it penetrates giving 
it a fine, red colour, and aiding in its preservation. 

2. Nitrate of bismuth has been mentioned as being 
the basis of pearl powder. # 

3. Nitrate of soda is found in beds of a mile or two 
in length in South America, and in smaller quantities in 
other parts of the world, generally in connexion with 
nitre, or, as it is more commonly called salt petre. 

4. Nitrate of silver, also called lunar caustic. It is 
very powerful in its effects in disorganizing animal sub- 
stances ; for this reason it is used to remove warts and 
other excresences ; it does this by a slow burning, oxygen 
leaving its old combination unites with the animal fibre, 
and thus decomposes it. The nitrate of silver is used 
in a weak solution for dyeing the hair black, it is also 
used for indelible ink. Nitric acid forms nitrates with 
most of the alkalies and the metals, but those which we 
have mentioned are the most important. 

IV. Genus Phosphates; these are salts arising 
from the combination of phosphoric acid with different 
bases. Its most important species are, 1. phosphate of 
lime, which forms an important part of the bones of an- 
imals, and is used in the manufacture of phosphorus : 
2. Phosphate of cobalt, by calcining with alum, forms a 
beautiful colour, called, after its discoverer, Thenard's 
blue. 

V. Genus Sulphates; none of the acids has a 
stronger tendency to unite with other substances than 
the sulphuric ; for this reason, the genus, sulphates con- 
tains many species. 



Of the nitrate of bismuth % 
Of the nitrate of soda 7 
Of the nitrate of silver - ? 

What is said of the genus phosphates, and which are its most 
important species 1 

What is said respecting the genus, sulphates? 



244 CHEMISTRY FOR BEGINNERS. 

1. Sulphate of lime, plaster of Paris or gypsum was 
at first used in the vicinity of Paris ; it is found common 
in various parts of the earth, sometimes in crystals, when 
it is called selenite, sometimes in large, rough masses, 
this is called plaster-stone. The many busts and other 
ornaments, resembling marble, which are now so com- 
mon, ar^e made of a pure and white plaster ; it is used 
under The name of stucco, to give to the outsides of 
buildings the appearance of marble, and is very use- 
ful as a manure, to promote the growth of vegetation. 
It is said that after Dr. Franklin's residence in France, 
where he had witnessed the effects of plaster in promot- 
ing vegetation, he wished to introduce its use into his 
own country. But the farmers believing that they knew 
better how to raise crops than he did, refused to follow 
his advice. Dr. Franklin was not accustomed to give 
way to discouragements, when he had a good object in 
view, and accordingly he caused a field to be pre- 
pared in the common way ; but in the middle of the 
field he wrote with plaster these words — Effects of Plas- 
ter, and then sowed the whole with grass seed. The 
grass soon appeared, and that which had been sown 
upon the plaster, far exceeded the rest in vigour and 
height. The Doctor then invited the farmers to go into 
his meadow; astonished with this indisputable evidence 
of its utility, they all hastened to enrich their fields with 
plaster manure. 

2. Sulphate of magnesia exists in solution in the wa- 
ters of Epsom and Seidlitz springs in Europe; from 
whence it is commonly called Epsom salts. 

3. Sulphate of Soda was first introduced into medicine 
by a physician of the name of Glauber ; from this cir- 
cumstance it is called Glauber's salts. 

4. Sulphate of potash is used in medicine ; it was 
formerly called vitriolated tartar, and its composition 
considered an important secret. 

What is said of sulphate of lime'? Of sulphate of magnesia'? 
Of sulphate of soda 7 Of sulphate of potash % 



SALTS CHROMATES. 245 

5. Sulphate of copper is commonly called blue vitriol ; 
it is found in a state of solution in copper mines. 

6. Sulphate of iron is called copperas, and sometimes 
green vitriol; this is important in the arts, especially in 
dyeing. Ink powder is made with this sulphate and a 
vegetable substance called nut-galls. 

7. Double sulphate of alumine and potash. This, 
though not strictly belonging to the genus sulphates, we 
shall here mention; it is the well known substance, 
alum. It is composed of 3 parts of the sulphate of al- 
umine, 174 

added to 1 part of the sulphate of potash, 88 



making the equivalent number of alum, 262 
The peculiar taste of alum is well known. It may be 
dissolved in boiling water. Beautiful large crystals for 
baskets and other ornamental work, may be obtained by 
evaporating its solutions. It is of great importance to 
the dyer in fixing those colours that are soluble in water. 

VI. Genus Chromates are composed of chromic 
acid with alkaline and metallic bases. All these salts 
are coloured, and many of them are valuable in the arts 
of dyeing and painting. 

Species 1. Chromate of lead is a brilliant yellow, 
sometimes called chrome yellow. 

2. Chromate of silver is of a deep purple colour. 

3. Chromate of potash is of a lemon yellow colour, 
and when melted it becomes green. It is used in calico 
printing, in painting, and in the preparation of chloric 
acid. 

We have now given an outline of the principal 
salts known in Chemistry, with the exception of some 
important ones which are formed in part, or entirely of 

What is said of sulphate of copper % Of sulphate of iron % 
Describe the doable sulphate of alumine and potash. 
What is said of chromates % 

Describe the species of this genus which are mentioned. 
What remark closes this chapter 1 



246 CHEMISTRY FOR BEGINNERS. 

vegetable compounds. But we could only notice, com- 
paratively, few of the whole number now known to 
chemists, exceeding, it is said, more than a thousand. 
You have seen something of the wonderful manner in 
which a few elements are made to unite, and form an 
almost infinite variety of substances. Thus it is in re- 
viewing the works of God, we are ever ready to exclaim, 
how simple, and yet how grand! 



CHAPTER XXI I I 



Organic Chemistry. Vegetable Chemistry. Vegetable 
Acids. Vegetable Alkalies. Oils, tyc. 

We have completed our view of Chemistry so far as 
relates to the mineral kingdom, under which we include- 
the water and air as well as stones, earths, and metals. 
The term inorganic, is applied to every thing in nature 
which is not animal or vegetable. 

Two great divisions may properly be made in Chem- 
istry, viz. : of inorganic and organic Chemistry ; we 
shall now briefly examine the latter. Vegetables and 
animals are called organic, because they are com- 



What is included under the mineral kingdom % 
What two divisions may be made in chemistry 7 
Why are vegetables and animals called organic, and other ob- 
jects in nature inorganic 7 



REMARKS ON ORGANIC CHEMISTRY. 247 

posed of parts or organs which are connected and mu- 
tually dependant on each other ; the remaining- objects in 
nature are called inorgajiic, because they do not consist 
of such parts, but every portion is a perfect specimen of 
its kind; and except in the case of crystals, which have a 
regular figure, they are shapeless masses of inert matter. 

We have found in the progress of our study of what 
elements these inorganic substances are composed ; the 
chemist, availing himself of this knowledge, is able to 
recompose many of them, or put them together after he 
has once destroyed their composition by analysis. 

The chemist is able to separate from their combina- 
tion the elements which compose animals and plants. 
He can tell us of what they are made, but he cannot 
put them together again, to make an animal or a plant; 
not even a weed, or the meanest worm that crawls, can 
be imitated by man in one respect, and that the one of 
all others which makes it what it is, a living thing. 

The living principle both in plants and animals is 
concealed from the search of man, although he has been 
prying into the mystery ever since satan tempted our 
first parents to disobey God, saying, 'thou shalt not 
surely die.' Their limbs were then active, the warm, 
current flowed in their veins, and they doubtless thought 
that these were properties of their bodies which could 
not be taken from them. But God commands, and 
plants and animals flourish in vigour and beauty; he 
says, let life depart, and they die and return to the dust 
from whence they came. 

All that can be done in organic Chemistry is to ex- 
amine, by means of chemical analysis, the elements of 
which bodies are composed, and to learn the various 
combinations which exist in animal and vegetable sub- 



Can the chemist recompose inorganic compounds 1 
Can he create animals and plants % 
What constitutes the living principle in organic beings % 
What can be done in organic chemistry 1 
21 



248 CHEMISTRY FOR BEGINNERS, 

stances. Of these substances new compounds have been 
formed, which have proved of great importance in the 
arts, and especially in medicine. 

Organic Chemistry is divided into Vegetable and An- 
imal Chemistry. 

Ultimate ^Elements of Vegetables. 

Organic substances when analyzed, are found to con- 
tain carbon, oxygen, hydrogen, sulphur, silex, the oxide 
of iron, soda, magnesia, and chalk. Iodine and bro- 
mine are obtained from sea weeds. Nitrogen is found 
in few plants, though it was formerly thought peculiar 
to animal and mineral substances. 

The ultimate elements of organic substances, such as 
carbon, oxygen, &c, are obtained by what is called de- 
structive distillation ; that is, submitting the vegetable 
matter to the action of heat in close vessels, and collect- 
ing all the products. Oxygen, carbon, and hydrogen 
form the most important ultimate elements of plants, al- 
though other substances are often found at their last or 
ultimate analysis. We shall not attempt to explain to 
the beginner the complicated process of analyzing or- 
ganic substances, which is so delicate, that little progress 
has hitherto been made in this department, in compari- 
son to what might have been expected from the discov- 
eries in inorganic Chemistry. 

Proximate principles are produced by plants and 
animals in their living state; these are gums, resins, 
honey, sugar, &c, besides various animal products. 

The ultimate elements of organic bodies are the same 
as those we have already examined under inorganic 

How is organic chemistry divided ? 

What are organic substances composed of? 

How are their ultimate elements obtained, and which are the 
most important ^ 

What are proximate principles 1 

Do the ultimate elements of organic bodies differ from those of 
inorganic bodies 1 



VEGETABLE CHEMISTRY. 249 

Chemistry. Plants are nourished by inorganic bodies, 
as the air, earth, and water. Animals feed on plants, 
and upon other animals which have gained their sub- 
sistence from plants. 

It is wonderful that of so few elements, such a vari- 
ety of combinations are produced ; in organic bodies, 
but few of the elementary substances which exist in 
nature are employed. A slight difference in the propor- 
tions of the elements, or in the manner in which they are 
put together or combined, seems to produce all this va- 
riety. 

Organized bodies are distinguished from inorganic by 
the following characters. 

1. Composed of the same elements, but in different 
proportions. 

2. Decomposed, in general, by a lower degree of heat. 

3. Cannot be produced by art. 

VEGETABLE CHEMISTRY. 

Proximate Principles of Plants. 

The proximate principles of plants are distinguished 
into two classes. 

Class i. contains such principles as carbon, oxygen, 
and hydrogen, without any nitrogen. This class is 
divided into three orders. 

1. Where oxygen is in excess; these are acids. 

2. Where hydrogen is in excess ; these are resins, oils, 
alcohol, <fyc. 

3. Where oxygen and hydrogen exist in the same 
proportions as in water ; these are gums, sugar, <fyc. 



What produces the variety which exists in organic substances, 
when so few elements are employed r l 

In what particulars are organic substances different from inor- 
ganic ? 

What elements compose the first class of proximate principles 1 

What are the orders of this class 1 



250 CHEMISTRY FOR BEGINNERS. 

Class ii. contains such principles as are composed 
of the elements of the first class, with the addition of ni- 
trogen ; this class includes vegetable alkalies. We can 
do little more than name a few of these proximate prin- 
ciples. 

Class i. — Order 1. Vegetable acids. 

Acetic acid exists in the sap of some plants and is the 
acidifying principle of vinegar. With various bases it 
forms acetates. Acetate of lead is the sugar of lead ; 
acetate of copper is verdigris. 

Oxalic acid is usually obtained from wood-sorrel, 
known in botany as belonging to the genus oxalis ; it ex- 
ists in several other plants. It is a powerful acid, and a 
fatal poison. 

Tartaric acid is obtained from the tamarind, the grape, 
and several other acid fruits ; combined with potash, it 
forms cream of tartar which is a tartrate of potash. Ro- 
chelle salt is a tartrate of potash and soda. 

Citric acid, is so called from the genus citrus, the 
lemon or orange, from which it is obtained. This 
often constitutes one of the powders sold under the name 
of soda powders, which consist of one paper of an acid, 
and another of an alkali, usually carbonate of soda. The 
efTervesence is caused by the escape of the carbonic acid, 
as the alkali unites to the new acid. Citric acid removes 
iron stains, though not as readily as oxalic acid. 

Malic acid from malus, the genus of the apple ; it 
is found in many other fruits, as currants, strawberries, 
&c. The flavor of fruits is chiefly owing to the citric, 
tartaric and malic acids which they contain. 

Gallic acid is obtained from nut galls, which grow 
upon the oak in consequence of the puncture of an in- 
sect that often deposites its eggs in the spot, and is 
therefore found in the centre of the nut. Gallic acid ex- 



What element does the second class of principles contain that 
does not exist in the first class 7 

What is said of acetic acid ] Of oxalic acid % Of tartaric 
acid 1 Of citric acid % Of malic acid % Of gallic acid ? 



VEGETABLE ACIDS. 251 

ists in white oak bark, with another principle called tan- 
nin. This acid turns iron black ; it is contained in tea. 
If you drop strong tea upon a knife, you will see a black 
spot upon the place. Gallic acid with tannin and sul- 
phate of iron forms ink and black dyes. The tannin 
unites with the sulphuric acid of the sulphate, and the 
iron is precipitated by the gallic acid in the form of a 
gallate of iron. 

Benzoic acid is obtained from a gum called benzoin, 
the product of a plant whose botanical name is sty rax 
benzoin; it is supposed to exist in the sweet-scented- ver- 
nal grass, [ant ho x ant hum odoratum.) It is used in the 
preparation of the paregoric elixir, and gives it a pecu- 
liar aromatic taste and smell. 

Kinic or quinic acid exists in peruvian bark, known 
in medicine as the cinchona bark. It is said to be formed 
of two equivalents of carbon, 12, four of hydrogen, 4, 
and three of oxygen, 24, this would make 40 its repre- 
sentative number. Indigotic acid is obtained from in- 
digo. 

Prussic acid is obtained from peach meats and blos- 
soms, bitter almonds, laurel, &c. It is now generally 
known in Chemistry as hydro-cyanic acid. 

Order 2. of proximate principles contain such as 
have hydrogen in excess, as oils, resins, &c. 

Oils are known by a greasy touch, by being easily in- 
flamed, and by not uniting with water, unless through 
the medium of an alkaline substance. 

Oils are of two classes, fixed and volatile ; the for- 
mer make grease spots on paper, as olive or sweet oil ; 
the latter fly off and leave no stain, as the oil of peper- 
mint, of cloves, &c. 

Fixed oils are usually obtained from the seeds of plants. 
Olive oil is pressed from the pulp of the olive berry 

What is said of benzoic acid % Of kinic acid ? Of prussic acid % 
What principles does the second order of the first class contain 1 
What are some of the properties of oils 1 
What two kinds of oils are there 1 
21* 



252 



CHEMISTRY EOR BEGINNERS. 



which is of the size of a small plum. The oil of flax- 
seed called linseed * oil dries without losing its transpa- 
rency ; this renders it valuable to painters, being 
used not only in house painting, but in nicer colouring 
of the limner. Oils which like linseed, dry rapidly 
the air are called drying oils. They combine with 
oxygen while drying, and much latent caloric is 
brought into a free state; — -if light combustibles, such 
as cotton or flax are wet with these oils there is danger 
of spontaneous combustion — this is one cause of the 
frequent burning of cotton and other manufactories. 
The kernels of walnuts and butternuts, on being heated 
and pressed, afford oil ; beech nuts and sunflower seeds 
are rich in the product. Palm and castor oil are used in 
medicine. 

Volatile oils give to plants their odour ; they are 
found in blossoms, fruit, leaves, barks, and roots, and are 
obtained by distilling them with water ; the common still 
is used for this purpose. The 
water and oil both flow into a vessel 
such as is here represented ; the 
water having reached the level a, b, 
runs off by the spout c ; and the oil 
being lighter, floats upon its sur- 
face in the space d. These oils are 
reduced by being mixed with alco- 
hol, they are then called essences. 
The oil of turpentine is the most 
"important of these substances ; it is 
much used in varnishing and in medicine. The oil of 
cloves is much recommended as a cure for the tooth 
ache : the oil of aniseseed, of pepperment, of nutmeg, 

* The botanical name of flax is linum from lin a thread ; from 
this comes linseed. 




Describe fixed oils, and mention the most important of them. 
What is said of volatile oils, and which are some of the most 
important 1 



VEGETABLE OILS. 253 

cinnamon, &c, are used in medicine, and by the house- 
keeper instead of the spices from which some of them 
are made. The oils are so powerful that one or two 
drops contain more of the real aroma of the plant than 
twenty or thirty drops of the essences. 

Camphor is classed among volatile oils; it is mostly 
obtained from Borneo and Sumatra, where it is extracted 
from the leaves of a large tree. In Japan it is found in 
the roots, branches and leaves of the Laurus Camphora. 
Camphor cannot be dissolved in water. Alcohol, or spirits 
containing it, are the best solvents for camphor. 

Resins are the dried juices of plants : they are of va- 
rious kinds. Gum resins; among these are the yellow 
substance used in painting and medicine called gam- 
boge : it is the juice of the gamboge tree, called in bota- 
ny the Stalagmitis gambogoides, from the the Greek 
stalagmos, a droping or distillation, because the gum es- 
capes in this manner. It grows in Gambaja in the East 
Indies. Aloes, myrrh, and Indian rubber belong to the 
gum resins. Indian rubber called also caoutchouc * or 
gum elastic is the resinous product of a tree found in hot 
countries. On exposure to the air it becomes brown like 
leather ; it can neither be dissolved by water or alcohol. 
Wax is obtained by bees from the pollen of flowers. 
The bay-berry plant f w T hich grows in sandy plains in 
the United States, near the sea shore, furnishes a kind of 
wax of a beautiful green colour, called by housekeepers 
bay-berry-tallow and used by them to mix with common 
tallow for candles. The vegetable wax makes them 
harder and gives them a fine clear appearance. 

* Pronounced ka-ot-chok. 

t Called in botany myrica cerifera ; the specifiic name cerifera 
means bearing wax. 



What can you say of camphor % 

"What are resins, and which are some of the most important 
gum-resins % 



254 CHEMISTRY FOR BEGINNERS. 

Alcohol is not a product of nature but is formed by the 
fermentation* of certain vegetable juices. It is the in- 
toxicating principle of liquors. If a mixture of one part 




of sugar, four of water, and a little yeast, be subjected to 
a suitable degree of warmth, the fermenting process 
begins, and carbonic acid gas may be collected; the 
figure shows the flask containing the fermenting mate- 
rials, and the receiver inverted over water into which the 
gas passes. In this process, carbon and oxygen forming 
the carbonic acid have been given off. Spiritous liquor is 
obtained by the distillation of fermented liquors. Spirits 
of wine or pure alcohol differs from wine, brandy or 
rum, only in being more thoroughly distilled. It is 
highly inflammable — many instances are recorded of the 
bodies of persons accustomed to the free use of alcohol 
or spirituous liquors burning, by taking fire internally. 
Though such cases of sudden spontaneous combustion 
are rare, yet every one, who, for a length of time indulges 
freely in the use of alcohol, experiences a slow com- 
bustion of the vitals and destruction of the mental powers. 

* For information respecting the various kinds of fermentation 
see Dictionary of Chemistry, pages 214, 215 and 216. 

What is said of alcohol ? 



ETHER SUGAR STARCH. 255 

It is useful in medicine, and is the only liquid which will 
dissolve many substances. Wine, cider and- ale contain 
alcohol combined with other vegetable principles and 
are therefore less intoxicating than brandy in proportion 
to the alcohol w^hich each contain ; in the latter the alco- 
hol is combined with water only, and thus acts directly 
upon the system. 

Ether is a term derived from the Greek (Ether, and 
signifies spirit. It is a liquor obtained by distilling alco- 
hol with a strong acid; its properties, must of course be 
very active. It is a powerful agent in medicine, and in 
Chemistry affords many striking experiments. On ac- 
count of its volatile nature, when exposed to the air it 
flies off in a gaseous form, and takes caloric from sur- 
rounding bodies. Sulphuric ether, which is obtained 
by distilling sulphuric acid with alcohol, is that which 
is in common 1 use. 

Order 3. Contains such principles, as have oxygen 
and hydrogen in the same proportions as they exist in 
water. 

Sugar is contained in ripe fruits, and in the sap of 
many trees and other plants, but is made in the United 
States, chiefly, from the sap of the maple. It has been 
made from beets, from the juice of cornstalks and grapes. 
Most of the sugar of commerce is made from the sugar 
cane, a plant which flourishes only in warm countries. 
Sugar is made by boiling and evaporating the juice of 
the sugar cane or other substance ; when properly made 
it is obtained in imperfect crystals. Molasses is the thick 
juice which runs off when the sugar is drained; it is 
called treacle. When exposed to the action of heat, sugar 
swells and diffuses a peculiar smell ; a large quantity of 
carbon remains after its combustion. 

Starch is a very abundant vegetable product ; it exists 

What is ether, how obtained, and what are some of its proper- 
ties 1 

What principles does the third order contain 1 
What is said of sugar and molasses 1 



256 CHEMISTRY FOR BEGINNERS. 

in the seeds, roots, and stems of plants. For domestic 
uses it is obtained from wheat, potatoes or Indian com. 
Among farmers in the country, it is very common for 
each family to manufacture their own starch. The green 
ears of Indian corn or potatoes are grated into large 
tubs of water ; the starch settles at the bottom : the water 
is then poured off, a fresh quantity of pure water added, 
and the starch broken up and again mixed with the water; 
it is then allowed to settle again. The process is re- 
peated until the starch is perfectly clean and white ; it is 
then laid on large platters and dried in the sun. There 
are now many starch manufactories ; near Utica is a vil- 
lage where the business is extensively carried on. Un- 
der the name of Poland starch, much that is made in the 
United States is sold. Starch is insoluble in cold water ; 
boiling water converts it into a jelly. Iodine gives with 
starch a blue colour, and its presence in any substance 
may always be known by this circumstance. Arrow 
root, sago and cassava resemble starch in most of their 
properties. 

Gum is a common proximate principle ; it is found 
upon many of our trees, as the cherry and plum tree. 
Gum Arabic is obtained from the species of a plant 
called mimosa, found in various parts of Africa and in 
Arabia. These gums differ from the gum-resins, already 
named, in their constituent principles ; the latter contain 
oil. 

Vegetable Alkalies. 

Class ii. of vegetable principles, contain such, as,-in 
addition to carbon, hydrogen, and oxygen, contain some 
nitrogen. These : are vegetable alkalies, or salifiable 
bases ; that is, they unite with acids to form salts ; they 
turn blue vegetable colours green, and exhibit some 



What is said of gum 7 
What principles does Class 2d contain ^ 

Where does starch existj how is it obtained, and what are some 
of its properties ? 



VEGETABLE ALKALIES. 257 

other properties of mineral alkalies. Most of them are 
poisonous. They are of modern discovery, and are 
now admitted to be among the most important articles in 
medicine. 

Morphia was first described in a manner to gain the 
notice of chemists in 1816, although it had been dis- 
covered by a German, engaged in the preparation of 
medicine, sometime before this. It is obtained from 
opium, which is itself the dried juice of the poppy. 
Morphia is supposed to be that principle in opium which 
causes sleep. Another alkali, called narcotine, is sup- 
posed to cause the sickening effects of opium ; as acids 
counteract these effects, citric and acetic acid are com- 
bined with it, forming a medicine lately introduced into 
use, under the name of ' the black drop.' 

Quinine and Cinchonia are alkaline substances, ob- 
tained by the analysis of the Cinchonia, or Peruvian 
bark. The sulphate of quinine is much used in medicine. 

Strychnine is the poisonous principle of the Bohon 
Upas tree of the island of Java, which is said to infect 
the air around it. This principle is found in some other 
plants. 

Emetine is extracted from a plant, called ipecacuanha, 
which grows in Brazil and Peru, and is well known as 
affording from its* root an emetic powder, sometimes 
called ipecac. The emetine is very powerful, as it con- 
tains the concentrated energy of the emetic principle. 

These peculiar principles seem to be almost as ex- 
tensive as the vegetable kingdom itself, and discoveries 
in this part of the field of science are continually made. 
The peculiar properties of the blood root (sanguinaria) 
are found in its extract sanguinarine ; of tobacco (nico- 
tiana)m nicotine ; of pepper in piperine ; and polenin is 
obtained from the pollen of plants ; it is very combust- 
ible, and putrefies in the air. 

What can you say of morphia 1 Of quinine % Of strychnine 1 
Of emetine 1 

Do these peculiar vegetable principles seem to be extensive in 
nature 1 



258" CHEMISTRY FOR BEGINNERS. 

The last division of vegetable principles, contains such 
as are not included under any particular class. There 
are some vegetable principles, that have not been ana- 
lyzed with sufficient accuracy to enable chemists to class 
them in relation to their elements. 

Colouring matter. The vegetable kingdom is rich 
in colouring matter; every young girl knows that saff- 
ron makes a fine yellow, and the leaves of one species 
of balm a beautiful red ; and most housekeepers in the 
country know that butternut bark affords a brown colour, 
and maple bark with copperas (sulphate of iron) fur- 
nishes a good black. 

Dyeing depends on a chemical affinity between the col- 
ouring matter and the fibres of the thing to be coloured. 
Wool receives colour the most readily of any substance; 
next to this is silk. 

Most colours require the agency of something to fix 
them firmly, or they w 7 ill be destroyed by washing. 
These intermediate agents are called mordants, from 
mordeo, to bite, as it was imagined that they corroded 
or eat into the fibres of the substance to be coloured; 
they are also called bases. Among the mordants used 
in dyeing are alum, copperas, and the oxides of tin and 
iron. These not only fix the colours, but often give 
them a brighter hue and a different shade. 

The most important colours in dyeing are blue, red, 
yellow, and black. 

Blue is chiefly obtained from a plant called Indigo ; 
it is cultivated in India, from whence it was first im- 
ported into Europe ; it is also cultivated in South Amer- 

Have the elements of all the vegetable principles been examin- 
ed'? 

Are there vegetable dyes 1 

On what principle does dyeing depend, and what substances 
receive colour most readily ? 

What are mordants, and which among them are most useful 1 

Which are the most important colours ? 

What is blue chiefly obtained from 1 



COLOURING MATTER TANNIN. 259 

ica, and in the southern United States. The botanical 
name of the plant is Indigofera ; of this genus there 
are several species. 

Red dyes are made from logwood, which grows in 
South America ; madder, the root of a plant ; safflower, 
the flower of a plant which grows near the Meditera- 
nean and from which rouge # is made ; litmus, a lichen 
plant, and cochineal, which is an animal substance, viz. 
a small insect that affords a rich carmine. 

Yellow is obtained from the American sumach, from 
turmeric, the root of an East Indian plant, saffron,] 
anotta, the seeds of a plant which grows in Cayenne and 
which is improperly called otter, and from some other 
substances. 

Black dyes are made like writing ink, of a compound 
consisting of the oxide of iron, gallic acid, and tannin ; 
logwood is also used. All the variety of shades of colours 
is produced by combining the different substances which 
have been mentioned. 

Tanm.n. We have mentioned this principle, and 
will here observe that, as its name would indicate, it is 
of important use in tanning leather. Those who have 
observed the vats of tanners, know that they contain 
large quantities of ground bark, of oak, hemlock, 
chesnut, &c. ; this bark contains the astringent principle 
tannin, which has a great affinity for gelatine, a substance 
which is abundantly contained in the skins of animals, 
and with which it forms a tough, insoluble compound, 
called leather. Gall nuts and the barks of most trees 
contain tannin ; it exists in tea with gallic acid. With 

* Pronounced rooje, the j soft. 

t The saffron, so called commonly, among us, is a compound 
flower, and not the true saffron, which belongs to the genus crocus, 
of the third class of Linnaeus. 

What are red dyes made from % 

What is yellow obtained from 7 

How are black dyes made \ 

What can you say respecting tannin, its use, properties &t\ 

22. 



260 CHEMISTRY FOR BEGINNERS. 

the peroxide of iron, tannin forms a dark coloured com- 
pound, which with the gallate of iron, forms black dyes 
and writing ink. 

Gluten constitutes a large portion of wheat flour ; after 
washing out the starch from flour, gluten remains in the 
form of a tough, adhesive paste. This substance is very 
nourishing, and renders wheat superior to other kinds of 
grain. Yeast makes bread light, on account of the gluten 
of the flour ; the carbonic acid gas in its attempt to es- 
cape, becomes entangled in it, and this causes the little 
cavities which are so numerous in light bread ; they were 
filled with the gas and air. If yeast is put into Indian 
meal, very little effect is produced, because it contains little 
or no gluten. Potatoes contain a large quantity of farina 
or starch which is nourishing, and wheat flour a large 
quantity of gluten ; they are therefore well adapted to 
each other, and good bread may be made by uniting 
them. Indian meal which is sweet, and favourable in its 
tendency to promote digestion, may be added to wheat 
flour in a considerable quantity, and the gluten of the 
latter with a suitable portion of good yeast, will prove 
sufficient to make the mass light. 

Yeast or emptins* is produced during the vinous fer- 
mentation of vegetable substances. This is a very im- 
portant article in domestic economy. Every house- 
keeper who does not live where she may procure yeast 
at the distillery, or brewery, will be attentive to keep by 
her a quantity of this article. Its effect in raising bread 
has been already noticed, under the article, gluten. In 
warm weather its operation is much more rapid than in 
cold ; the bread becomes light in a few hours, or 
goes through what is called the vinous fermentation ; it 

*So named from being left at the bottom of beer, and at first 
called emptyings. 

Give some account of gluten. 

How is yeas! produced, what makes bread sour, and how can 
this be remedied % 



ANIMAL CHEMISTRY. 261 

then proceeds to the acid fermentation, and the lazy 
housekeeper who made her bread at night finds her 
dough has soured while she was indulging in her morn- 
ing nap. But there is for this misfortune a remedy. If 
a solution of pearlash or the carbonate of potash be 
kneaded into the dough, the acetic acid will leave the 
dough and unite with the potash, and carbonic acid 
(which though possessing some properties in common 
with acids is not sour,) will diffuse itself in the meshes of 
the gluten and help to make the bread lighter. But lest 
this knowledge should encourage carelessness, we will 
remark, that when dough has gone through this process, 
although the bread may be lighter, and free from an 
acid taste, yet it will not be sweet and pleasant as that 
which has never been soured. 



CHAPTER XXIV, 

Organic Chemistry. 
ANIMAL CHEMISTRY. 

We shall not attempt to treat scientifically upon that 
part of Chemistry which more than any other, baffles the 
skill of the learned. Physicians and anatomists, search 
into the different substances which compose the animal 
frame ; they tell us that blood is composed of albumen, 
fibrin, water, and some mineral substances. They ex- 
amine the contents of the stomach, and find there a sub- 
Is it easy to understand Animal Chemistry 1 



262 CHEMISTRY FOR BEGINNERS. 

stance which they call the gastric juice, and whose 
office it is to dissolve the food that is introduced into 
its region ; but the cause of the circulation of the blood, 
without which life ceases, and the manner in which the 
gastric juice performs its analysis, no physician or chem- 
ist can explain. 

The animal system seems to present a .wonderful lab- 
oratory, where, with only a few simple elements to ope- 
rate with, a new and peculiar class of substances is com- 
posed ; and decompositions are carried on upon principles 
wholly concealed from human observation. Should the 
great Creator condescend to reason with man, as with 
his servant of old, might he not say to him, ' behold the 
cumbrous machinery with which thy operations are 
performed, and then turn from them to this human 
frame ! Canst thcu tell how its breathing is carried on, 
how the heart has power at every instant to send forth 
the vital current, which, in ten thousand courses, rushes 
to every part of the system, and then in new avenues re- 
turns to its living fountain % Dost thou know how the 
lungs perform their part in the curious machinery, con- 
veying to the blood the vital air, and conducting off that 
which is unfit for farther use?' Man, in the language 
of Job, must reply, ' I am vile, what shall I answer thee? 
I know that thou canst do everything.' 

Ignorant as we are, and must be, respecting the com- 
plicated machinery of the living body, much may be 
learned respecting the action of different substances upon 
the animal system. The physician observes the effect 
of different medicines ; like the chemist, he makes his 
experiments, but while the chemist in controlling inert 
maiter always produces the same effects, the physician 
often finds his efforts defeated, and his most powerful 
medicines fail. 



"What is remarked of the wonderful machinery of the animal 
system % 

What is said of the difference between the experiments of the 
physician and the chemist 1 



GELATINE. 263 

The human stomach, and the whole human frame, 
though partaking of a common nature with inorganic 
matter, are yet controlled by a power which that does not 
possess, and whose influence often defeats, or, in an un- 
expected manner, assists the experiments of the physi- 
cian. The mind is this power — if that is disturbed, the 
material portion of man is interrupted in its functions. 
The quick beating of the heart, the throbbing of the 
temples, the rush of blood to the mantling cheek, or the 
sudden paleness of the fatures are often caused by men- 
tal excitement — and the mind, as was remarked in our 
introductory chapter, is no subject for chemical inquiries. 
It is when mind has left it, that this earthly tenement, 
may be fully examined and analyzed by the chemist — but 
then he has nothing before him but matter, and matter 
hastening to blend with its native inorganic elements. 

We will now notice a few of the most important ani- 
mal substances. The ultimate elements you will recol- 
lect are the same as those of vegetables, consisting chiefly 
of carbon, oxygen and hydrogen — but in animal sub- 
stances nitrogen, which seldom exists in vegetables, is 
one of the constituents. 

The proximate principles of animal matter are pecul- 
iar to itself, differing from those of plants, not only in 
the circumstance of their containing nitrogen, but in 
their rapid decay and putrifaction, during which, they 
throw off offensive gases. 

Gelatine is that soft, jelly like substance which is so 
abundant in the head and feet of calves. It is this which 
renders soup nourishing; it may be obtained from 
almost any kind of meat by boiling it a sufficient time, 



What is said of the power which controls the inorganic matter 
of which the body is composed % 

Are the ultimate elements of animal substances different from 
those of vegetables 1 

What is said of the proximate principles of animal matter 

What is gelatine, and what are its properties 1 

22* 



264 CHEMISTRY FOR BEGINNERS. 

cooling it to remove the fat which rises at the top, and 
straining to separate it from the fibres of the meat. The 
skins of animals are mostly composed of gelatine. On 
account of the tough and hard compound which it forms 
with tannin, skins are made into leather. Glue is made 
by boiling the skins and other parts of animals, and 
isinglass is made from fish gelatine. 

Fat is an animal product which is used under various 
forms. Lard is the fat of swine, tallow of neat cattle ; 
spermaceti is the fat found in the head of the whale, lamp 
oil is from the body of the whale. United to potash and 
other alkalies, all kinds of fat may be converted into 
soap. 

Fibrin forms most of the flesh and muscles of ani- 
mals. It exists in blood. If with a bundle of twigs or 
a little brush from a broom some fresh blood be beaten, 
long reddish filaments will be found adhering to the 
twigs ; this is fibrin, which on being washed in cold 
water becomes colourless. Its ultimate elements are thus 
stated by a French chemist. 



Carbon 


50 parts 


Nitrogen 


20 


Oxygen 


20 " 


Hydrogen 


10 " 



100 

Albumen is found in its purest state in the white of an 
egg, where it exists with w r ater and a little soda. It is 
also found in a solid state in s?me parts of the body, and 
liquid in milk and other animal substances. The facili- 
ty with which albumen coagulates or hardens, is appa- 
rent from the quickness w T ith which the white of an egg 
cooks in boiling water. 

What are the different kinds of animal fat ? 

Where does fibrin exist, and what are the proportions of its 
elements % 

Where does albumen exist, and for what property is it re- 
markable ? 



BLOOD — MILK — BUTTER. 265 

Blood is composed of water, albumen, fibrin and some 
salts and oxides. Its colour is supposed to be owing to 
the oxide of iron. It is a deep purple until oxygen 
gives it a lively red colour. In breathing there are two 
processes, the drawing in of the breath called inspira- 
tion, and the throwing out of the breath called expiration ; 
in the former, the air which contains oxygen is inhaled, 
this mingling with the blood changes it from a dark to a 
bright red colour, and is carried from the lungs to the 
heart; in the latter process carbonic acid is thrown from 
the lungs. You have only to breathe through a tube into 
a tumbler of lime water, and you will see the evidence 
that you throw off carbonic acid, in the fact that the lime 
water acquires a milky appearance as if chalk had been 
mixed with it ; this is in consequence of carbonate of 
lime being formed by the carbonic acid, from the breath 
uniting with the lime. Blood on being taken from the 
veins if suffered to stand for a short time separates into 
two parts, one thick and dark coloured called the cruor, 
and the upper portion light coloured and watery, called 
the serum. 

Milk contains three parts, the cream which on account 
of its being lighter rises to the surface, the caseous or 
cheesy substance and the serum or whey ; the two latter 
are separated by means of rennet. This is obtained 
from the stomach of calves, which affords a peculiar 
substance capable of curdling milk ; in which process 
the cheesy or caseous part is separated from the whey or 
serum. 

Butter is obtained by agitating cream in a vessel called 
a churn; during this operation the particles of butter 
unite, and the cream is transformed into butter and 
buttermilk ; the latter is serum containing caseous or 



Give some account of blood, its composition, the effect of oxy- 
gen upon it, the process of breathing, &c. 
Of what parts does milk consist 1 
What takes place during the operation of churning batter ? 



266 CHEMISTRY FOR BEGINNERS. 

cheesy particles. Butter has been found to consist of an 
acid called butyric acid, stearine and elaine, two sub- 
stances which form the basis of all kinds of fat, and a pe- 
culiar substance called butyrine. 

It is the province of animal Chemistry to explain the 
nature and constituents of bones, teeth, hair, wool, silk, 
feathers, fyc. in short of every substance which either en- 
ters into the animal organization, or which is the product 
of this organization during its active state. Under the lat- 
ter head are, saliva, tears, bile, gastric juice, fyc. By 
referring to a Dictionary of Chemistry or to larger works 
these subjects may be examined by the pupil, who com- 
prehending what has been explained to him, feels a de- 
sire for farther information. 

We have now, as far as science has penetrated into the 
composition of the material things which compose the 
globe, explained to you of what they are made, and how 
they are put together. We have taught you the alpha- 
bet of nature, or her simple elements ; and shown you 
that by different combinations of them, all the various 
substances which the earth presents are formed. You 
have now learned to understand chemical language. 
The Beginner in Chemistry who has carefully studied 
the great laws of affinity, the powerful agency of caloric 
and electricity in uniting and disuniting substances, the 
wonderful properties of that all pervading element, ox- 
ygen, and the relation of other substances to it ; who has 
traced the combinations of supporters of combustion 
w r ith combustible bodies, and observed the regular pro- 
portions in which they are united, is prepared to under- 
stand chemical books and lectures, and to investigate for 
himself the great volume of nature. 



What is buttermilk, and of what parts does butter consist 1 
What subjects properly belong to animal chemistry 7 
Repeat the concluding remarks. 



INDEX. 



A. 

Acids, 230 

" vegetable, 250 

Affinity, simple, 17 

Air atmospheric, 103 

Alcohol, 254 

Alkalies, vegetable, 256 

Alumine," 210 

Analysis, 16 

Aqua Fortis, 105 

Arsenic, 224 

Attraction, 13 

B. 

Barium, 205 
Bi-carburetted Hydrogen, 185 

Bismuth, 222 

Blow-pipe, 129 

Boiling, 66 

Roron, 160 

Borax, 159 

Bromine, 167 

C. 

Cadmium, 227 

Calcium, 204 

Caloric, 37 

Carbon, 146 

Carbonate of lime, 9 

Carbonic acid, 152 

oxide, 156 
Carburetted Hydrogen, 182, 187 

Cerium, 229 

Chalk, 9 



Charcoal, 148 

Chemical affinity, 17, 25 

" attraction, 13, 15 

Chemistry, 7 

" definition of, 9 

" organic, 261 

Clorates, 239 

Chlorides, 232 

Chlorine, 174 

Chromates, 245 

Chromium, 225 

Coal gas, 183 

Cobalt, 223 

Colours, 34 

Combustion, 73 

Copper, 219 

D. 

Definite proportion, 25 

law of 107 

Diamond, 146 

Double elective affinity, 22 



E. 

Electric machine, 

Electricity, 

Ether, 

Eudiometer, 

Evaporation, 



F. 



Fluoric acid, 

Fluorine, 

Freezing, 



79 

76 

255 

141 

56 



165 

164 

63 



268 


INDEX. 




g. 




O. 


~ 


Galvanism, 


82 


Oil gas, 


184 


Gases, 


16,90 


" of vitriol, 


20 


Glauber's salts, 


21 


Oils, 


251 


Gluten, 


260 


Osmium, 


227 


Gold, 


217 


Oxides, 


237 






Oxygen gas, 


92 


H. 




P. 




Heat, 


37 




Hydro-chlorates, 


242 


Palladium, 


226 


Hydrogen, 


114 


Phosphates, 


243 


Hydro-nitrous acid, 


Phosphorus, 


139 






Platinum, 


216 


I. 




Potash, 


25, 198 






Prism, 


33 


Iodine, 


162 


Prussic acid, 


195 


Iridium, 


226 






Iron, 


219 


R. 




L. 




Rhodium, 


226 






Resins, 


253 


Lead, 


220 






Light, 


31, 36 


S. V 




Lime, 


202 






Lithium, 


205 


Safety lamp, 


190 






Salts, 


234 


M. 




Saturation, 


26 






Selenium, 


138 


Magnesia, 


207 


Silex, 


207 


Magnetism, 


86 


Silicon, 


208 


Manganese, 


225 


Silver, 


217 


Mercury, 


218 


Soda, 


201 


Metalloids, 


197, 206, 215 


Strontium, 


206 


Metals, 


212 


Sulphates, 


243 


Molybdenum, 


228 


Sulphur, 


130 


Motion, 


40 


Sulphuric acid, 


25, 135 


Muriatic acid, 


169 


Sulphurous acid, 


134 






Sulphuretted hydrogen. 


191 


N. 




Steam, 


67 


Nickel, 


227 


Synthesis, 


16 


Nitrates, 


242 


T. 




Nitric acid, 


105 






" oxide, 


110 


Tannin, 


259 


Nitrogen, 


100 


Thermometer, 


46 


Nitrous acid, 


109 


Tin, 


221 


" oxide, 


112 


Tungsten, 


228 







INDEX. 




^t>y 


Uranium, 


U. 


228 Water, 
Winds, 


W, 


182 
56 


Vanadium, 
Vapour, 


V. 


229 Yeast ' 
67 

Zinc, 


Y. 


260 
222 



